UNITED STATES
                         SECURITIES AND EXCHANGE COMMISSION
                                Washington, D.C. 20549

                               ________________________


                                      FORM 20-F/A
                                  (Amendment No. 1)

                               ________________________

   REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES
   EXCHANGE ACT OF 1934

                                       -OR-

X  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT
   OF 1934 for the fiscal year ended December 31, 2005

                                       -OR-

   TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
   ACT OF 1934 (NO FEE REQUIRED) for the transition period from _____ to ______

   Commission File Number: 000-30126

                               ________________________


                                   ACAMBIS PLC
          (Exact name of Registrant as specified in its charter)

                                  Not Applicable
               (Translation of Registrant's name into English)

                                England and Wales
               (Jurisdiction of incorporation or organization)

    Peterhouse Technology Park, 100 Fulbourn Road, Cambridge, CB1 9PT England
                    (Address of principal executive office)

                               ________________________


  Securities registered or to be registered pursuant to Section 12(b) of the
                                     Act: None

Securities registered or to be registered pursuant to Section 12(g) of the Act:

                         Ordinary Shares of 10 pence each
                               (Title of Class)

Securities for which there is a reporting obligation pursuant to Section 15(d)
                                    of the Act:
                                      None

                               ________________________

Indicate the number of outstanding shares of each of the issuer's classes of
capital or common stock as of the close of the period covered by the annual
report.

           Ordinary Shares: 107,351,407 as of December 31, 2005

                               ________________________


Indicate by check mark if the registrant is a well-known seasoned issuer, as
defined in Rule 405 of the Securities Act.      Yes     No X

If this report is an annual or transition report, indicate by check mark if the
registrant is not required to file reports pursuant to Section 13 or 15(d) of
the Securities Exchange Act of 1934.            Yes     No X

Indicate by check mark whether the registrant: (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.       Yes X   No

Indicate by check mark whether the registrant is a large accelerated filer, an
accelerated filer, or a non-accelerated filer. See definition of "accelerated
filer and large accelerated filer" in Rule 12b-2 of the Exchange Act.

Large Accelerated Filer        Accelerated Filer X     Non-Accelerated Filer

Indicate by check mark which financial statement item the registrant has
elected to follow:  Item 17 X   Item 18

If this is an annual report, indicate by check mark whether the registrant is a
shell company (as defined in Rule 12b-2 of the Exchange Act).  Yes   No X


Enclosure: Annual Report on Form 20-F/A


                           EXPLANATORY NOTE

         This Annual Report on Form 20-F/A ("Form 20-F/A") is being filed by
Acambis plc (the "Company" or the "Registrant") as Amendment No. 1 to the
Registrant's Annual Report on Form 20-F for the fiscal year ended December 31,
2005 ("Form 20-F").  This Form 20-F/A is filed with the Securities and Exchange
Commission (the "Commission") solely for the purpose of including additional
disclosures in Items 15 and 17 regarding the Company's Controls and Procedures
and Financial Statements, respectively.

         This Form 20-F/A does not otherwise amend, restate, change or update
the disclosures set forth in the Form 20-F as originally filed on June 28,
2006, and does not reflect events occurring after the original filing of the
Form 20-F.


Item 15.  Controls and procedures.

A    Disclosure controls and procedures

The Board has applied  principle  C.2 of the  Combined  Code by  establishing  a
process for identifying, evaluating and managing the significant risks the Group
faces.  This  process  has  been in  place  since  the  start  of 2000 and is in
accordance  with Internal  Control:  Guidance for Directors on the Combined Code
published in September  1999. The Board is responsible  for the Group's  overall
system of controls and  procedures and for reviewing its  effectiveness.  Such a
system  manages rather than  eliminates the risk of failure to achieve  business
objectives.

The Board  regularly  reviews the risks to which the business is exposed and the
controls  in place  to  mitigate  those  risks.  It  delegates  the  operational
management of the business risk process to the  Executive  Directors,  including
the Chief Executive  Officer and the Chief Financial  Officer,  who in turn have
put in  place  a  specific  working  group  comprising  senior  management  from
different areas of the business to carry out reviews on a periodic  basis.  From
2005, the Operations  Committee,  which comprises senior  operational  managers,
reports to the Executive  Committee,  and which has oversight of the  day-to-day
operational  activities of Acambis,  has been  responsible for managing the risk
reviews.

In conjunction with the reviews described above, the Chief Executive Officer and
Chief Financial  Officer evaluated the effectiveness of the design and operation
of the  Company's  disclosure  controls and  procedures as of December 31, 2005.
Based upon that  evaluation,  the Chief  Executive  Officer and Chief  Financial
Officer concluded that the design and operation of these disclosure controls and
procedures  were  effective as of December 31, 2005. The controls and procedures
referred to in our evaluation and conclusion of  effectiveness  also  constitute
"disclosure controls and procedures" as defined in Rules 13a-15(e) and 15d-15(e)
under the Securities Exchange Act of 1934, as amended (the "Exchange Act).

B    Management's annual report on internal control over financial reporting

In compliance  with provision  C.2.1 of the Combined Code, the Board reviews the
effectiveness of the Group's system of internal control.  The Board's monitoring
covers all material controls,  including  financial,  operational and compliance
controls and risk management.  It is based,  principally,  on reviewing  reports
from management to consider whether significant risks are identified, evaluated,
managed and  controlled  and whether any  significant  weaknesses  are  promptly
remedied or indicate a need for more  extensive  monitoring.  The Board has also
performed a specific  assessment  for the purpose of this Annual  Report on form
20-F considering all significant  aspects of internal control arising during the
year.  The  Audit  Committee   assists  the  Board  in  discharging  its  review
responsibilities.

The Combined Code was republished in July 2003 and restated in July 2005 by the
Financial  Reporting Council and incorporated the previous code (as  published
in 1998 by the Hampel  Committee)  and related  guidance that had been issued
since that date:  the  Turnbull  Guidance on Internal  Control;  the Smith
Guidance On Audit Committees;  and various items of good practice guidance from
the  Higgs  Report.  The  code has been  applicable  for  reporting  years
beginning on or after  November 1, 2003 and,  therefore,  was adopted by Acambis
from its 2004  financial  year,  which began on January 1, 2004.  The overriding
principle of the Combined Code is that  companies must comply with it or explain
why they have not. The following section highlights the areas where Acambis
previously did not comply with the code and notes the progress made to address
those areas:

_______________________________________________________________________
CODE PROVISION                       PROGRESS MADE SINCE PUBLICATION OF
                                     THE 2004 FORM 20-F
_______________________________________________________________________
B REMUNERATION                       A disclosure is made in the
B.2.1 A statement on whether         Corporate Governance Statement in
remuneration consultants have any    the 'Remuneration Committee'
other connection with the Company    section. A statement has been
should be available on the Acambis   available on the Acambis website
website.                             since early 2005.
_______________________________________________________________________
C ACCOUNTABILITY AND AUDIT           In November 2004, the Audit
C.3.4 Arrangements should be in      Committee approved a whistleblowing
place for the reporting and          policy. The procedure was developed
management of concerns raised by     during 2005 and rolled out to the
staff about possible financial or    Group in early 2006.
other improprieties.
_______________________________________________________________________

The information  contained within this Item 15B is voluntarily  provided, on the
principle  of  providing  substantially  similar  disclosure  to  our  UK and US
security-holders.  This disclosure is not a report of management on our internal
control over financial  reporting as defined in Exchange Act Rules 13a-15(f) and
15d-15(f).

C    Not applicable

D    Changes in internal control over financial reporting

During the  period  covered by this  Annual  Report on Form 20-F,  there were no
changes in the Group's internal control over financial  reporting  identified in
connection  with  management's   evaluation  of  such  control  that  materially
affected,  or are reasonably likely to materially  affect,  the Group's internal
control over financial reporting.

Item 17.  Financial Statements.

DIRECTORS'  RESPONSIBILITIES
Company  law  requires  the  Directors  to prepare financial  statements  for
each financial year that give a true and fair view of the state of  affairs  of
the  Group and of the  profit or loss of the Group for that period.

FINANCIAL STATEMENTS, INCLUDING ADOPTION OF GOING CONCERN BASIS
After making  enquiries,  the Directors have a reasonable  expectation  that the
Group has  adequate  resources  to continue  in  operational  existence  for the
foreseeable  future.  For this reason,  they continue to adopt the going concern
basis in preparing the financial statements.
In preparing the financial statements, the Directors are required to:
- select suitable accounting policies and then apply them consistently;
- make judgments and estimates that are reasonable and prudent;
- state whether applicable accounting standards have been followed, subject to
  any material departure disclosed and explained in the financial statements;
  and
- prepare the financial statements on the going concern basis unless it is
  inappropriate to presume that the Group will continue in business.

The  Directors  are  responsible  for keeping  proper  accounting  records  that
disclose  with  reasonable  accuracy at any time the  financial  position of the
Group and enable them to ensure that the  financial  statements  comply with the
Companies Act 1985. They are also responsible for safeguarding the assets of the
Group and, hence,  for taking  reasonable steps for the prevention and detection
of fraud and other irregularities.

The Directors are  responsible  for the maintenance and integrity of the Group's
website.  Uncertainty regarding legal requirements is compounded, as information
published on the Internet is accessible in many countries  with different  legal
requirements   relating  to  the  preparation  and  dissemination  of  financial
statements.

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

TO THE BOARD OF DIRECTORS AND THE SHAREHOLDERS OF ACAMBIS PLC
In our opinion,  the accompanying  consolidated  balance sheets, and the related
consolidated income statements,  the consolidated statement of recognized income
and  expenses and  consolidated  cash flow  statements  present  fairly,  in all
material respects, the financial position of Acambis plc and its subsidiaries at
31 December 2005 and 2004,  and the results of their  operations  and their cash
flows  for  each of the two  years in the  period  ended 31  December  2005,  in
conformity with International  Financial  Reporting  Standards as adopted by the
European  Union.  These  financial  statements  are  the  responsibility  of the
Company's  management;  our  responsibility  is to  express  an opinion on these
financial  statements  based on our  audits.  We  conducted  our audits of these
statements in accordance  with the  standards of the Public  Company  Accounting
Oversight  Board  (United  States).  Those  standards  require  that we plan and
perform the audit to obtain  reasonable  assurance  about  whether the financial
statements are free of material misstatement.  An audit includes examining, on a
test basis,  evidence  supporting  the amounts and  disclosures in the financial
statements,  assessing the accounting  principles used and significant estimates
made by management, and evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

International  Financial  Reporting  Standards as adopted by the European  Union
vary in  certain  significant  respects  from  accounting  principles  generally
accepted in the United States of America. Information relating to the nature and
effect of such differences is presented in Note 28 to the consolidated financial
statements.

PricewaterhouseCoopers LLP
Cambridge, England
June 26, 2006



CONSOLIDATED INCOME STATEMENT FOR THE YEARS ENDED DECEMBER 31

                                                         2005          2004
                                               Notes     GBPm          GBPm
___________________________________________________________________________
Revenue                                           2      40.9          85.5
Cost of sales                                           (27.6)        (35.0)
___________________________________________________________________________
Gross profit                                             13.3          50.5
Research and development costs                          (34.1)        (29.3)
Sales and marketing costs                                (2.6)         (2.8)
Administration costs (including costs
relating to Canton plant impairment and
restructuring costs)                              3      (7.7)         (5.5)
Other operating income - settlement of Canton
agreement                                         3         -          10.2
Other operating income - fair value of shares
received for grant of license                     3       0.4             -
___________________________________________________________________________
Operating (loss)/profit                            4    (30.7)         23.1
Finance income                                     3      4.0           4.8
___________________________________________________________________________
Finance costs                                      3     (1.0)         (0.9)

(Loss)/profit on ordinary activities before
taxation                                               (27.7)          27.0
Taxation - UK                                      5    (1.7)          (3.7)
Taxation - overseas                                5     2.4           (3.6)
___________________________________________________________________________
(Loss)/profit on ordinary activities after
taxation attributable to shareholders                   (27.0)         19.7
___________________________________________________________________________
Basic (loss)/earnings per ordinary share (in
pence)                                           6      (25.2)p        18.5p
Diluted (loss)/earnings per ordinary share
(in pence)                                       6      (25.2)p        18.1p
___________________________________________________________________________

A statement of changes in equity is given in note 23.

The accompanying notes are an integral part of this consolidated income
statement.

All amounts in 2005 and 2004 arise from continuing operations.


CONSOLIDATED STATEMENT OF RECOGNIZED INCOME AND EXPENSES FOR THE YEARS ENDED
DECEMBER 31
                                                     2005         2004
                                                     GBPm         GBPm
_______________________________________________________________________
Retained (loss)/profit for the year                 (27.0)        19.7
Gain/(loss) on foreign currency exchange              1.6         (2.5)
Revaluation of available-for-sale investment (net
of deferred tax)                                      0.1            -
Total (expense)/income recognized for the year      (25.3)        17.2
_______________________________________________________________________


CONSOLIDATED BALANCE SHEET AT DECEMBER 31

                                                            2005        2004
                                                     Notes  GBPm        GBPm
____________________________________________________________________________
Assets
Non-current assets
Goodwill                                               7    14.9        15.4
Other intangible assets                                8     4.2         4.1
Property, plant and equipment                          9    19.8        18.5
Deferred tax asset                                     5     0.3           -
Financial assets: available-for-sale investment       11     0.6           -
Other non-current assets                              12       -         2.5
____________________________________________________________________________
                                                            39.8        40.5
____________________________________________________________________________
Current assets
Inventory                                             13     3.6         6.0
Current tax assets                                           1.3         1.9
Trade and other receivables                           14    20.6        13.7
Financial assets: derivative financial instruments    15     0.1           -
Liquid investments                                    15    18.8        20.8
Cash and cash equivalents                             16    49.2        81.0
____________________________________________________________________________
                                                            93.6       123.4
____________________________________________________________________________
Liabilities
Current liabilities
Financial liabilities:
- short-term borrowings                               17    (4.0)      (3.6)
- short-term financial liabilities                    17    (7.2)      (3.1)
- derivative financial instruments                    15       -        (0.1)
Trade and other payables                              18   (16.1)       (8.3)
Accruals and deferred income                               (14.1)      (27.9)
Income tax payable                                          (3.1)       (4.6)
Provisions                                            19    (2.3)          -
____________________________________________________________________________
                                                           (46.8)      (47.6)
____________________________________________________________________________
Net current assets                                          46.8        75.8
____________________________________________________________________________
Non-current liabilities
Investment in Joint Venture                           20    (0.3)       (0.3)
Long-term financial liabilities                       17    (1.6)       (6.3)
Other non-current liabilities                         21       -        (0.5)
Deferred tax liabilities                               5    (1.7)       (1.7)
____________________________________________________________________________
                                                            (3.6)       (8.8)
____________________________________________________________________________
Net assets                                                  83.0       107.5
____________________________________________________________________________

Shareholders' equity
____________________________________________________________________________
Share capital                                         22    10.7        10.7
Share premium                                         23    98.0        97.8
Other reserves                                        23    (0.9)       (2.5)
Retained earnings                                     23   (24.8)        1.5
____________________________________________________________________________
Total shareholders' equity                                  83.0       107.5
____________________________________________________________________________

The financial  statements were approved by the Board of Directors on May 9, 2006
and were authorized for issue on its behalf by David  Lawrence,  Chief Financial
Officer.

CONSOLIDATED CASH FLOW STATEMENT FOR THE YEARS ENDED DECEMBER 31

                                                             2005        2004
                                                      Notes  GBPm        GBPm
_____________________________________________________________________________
Operating activities
(Loss)/profit on ordinary activities before tax             (27.7)       27.0
Depreciation and amortization                                 5.3         6.3
Increase in working capital                                  (2.8)      (51.1)
Other non-cash movements                                     (0.7)        2.6
Net finance costs                                            (3.0)       (3.9)
Taxes paid                                                   (0.4)       (1.6)
_____________________________________________________________________________
Cash flows from operating activities                        (29.3)      (20.7)
_____________________________________________________________________________
Investing activities
Purchase of business operations                              (1.7)       (0.8)
Disposal of investments                                         -         0.7
Purchase of intangibles                                      (0.4)          -
Purchase of property, plant and equipment                    (3.7)       (3.4)
_____________________________________________________________________________
Cash flows used in investing activities                      (5.8)       (3.5)
_____________________________________________________________________________
Financing activities
Interest element of finance lease payments                   (0.6)       (0.7)
Interest paid                                                (0.2)       (0.1)
Interest received                                             3.8         4.4
Proceeds from issues of shares                                0.2         1.9
Purchase of own shares                                 23    (0.2)          -
Capital element of finance lease payments                    (3.3)       (2.5)
Purchase of liquid investments                              (34.8)      (62.6)
Sale of liquid investments                                   36.8        59.6
_____________________________________________________________________________
Cash flows from financing activities                          1.7           -
_____________________________________________________________________________
Decrease in cash and cash equivalents                       (33.4)      (24.2)
Net foreign exchange difference                               1.6        (2.2)
Cash and cash equivalents at January 1,                16    81.0       107.4
_____________________________________________________________________________
Cash and cash equivalents at December 31,              17    49.2        81.0
_____________________________________________________________________________


Notes to the Group financial statements

1 ACCOUNTING POLICIES

BASIS OF PREPARATION
The  consolidated  financial  statements  of Acambis  plc have been  prepared in
accordance  with  IFRS and  International  Financial  Reporting  Interpretations
Committee  interpretations  that have been adopted for use in the European Union
and with those parts of the Companies Act 1985 applicable to companies reporting
under IFRS. In the context of Acambis plc's consolidated  financial  statements,
there is no difference between IFRS as adopted by the European Union and IFRS as
published by the IASB. The consolidated  financial statements have been prepared
on a historical cost basis as modified by the revaluation of  available-for-sale
investments,  except  for  derivative  financial  instruments  which  have  been
measured at fair value. The consolidated  financial  statements are presented in
pounds  sterling and all values are rounded to one decimal  point of the nearest
million (GBPm) except where otherwise indicated.

The preparation of financial  statements in conformity  with generally  accepted
accounting  principles requires the use of estimates and assumptions that affect
the  reported  amounts of assets and  liabilities  at the date of the  financial
statements and of revenues and expenses  during the reporting  period.  Although
these estimates are based on Management's best knowledge of the amount, event or
action, actual results may ultimately differ from those estimates.

CHANGE IN ACCOUNTING POLICY
The consolidated financial statements of Acambis plc have been prepared, for the
first time, in accordance with IFRS. The effect of adoption of IFRS is described
in note 27 of these financial statements.  A summary of the more important Group
accounting  policies  is set out  below.  These  accounting  policies  have been
consistently applied in the preparation of these financial statements.

TRANSITIONAL PROVISIONS
The rules  for  first-time  adopters  of IFRS are set out in IFRS1  'First  time
adoption of IFRS',  which allows certain  transitional  provisions.  Acambis has
applied the exemption  granted by IFRS1 to goodwill acquired before August 2003.
The value of goodwill  relating to the  acquisition  of Acambis  Inc. in 1999 is
frozen as at January 1, 2004,  whilst that relating to the acquisition of BPC in
August 2003 has been restated in accordance with IFRS3 'Business combinations'.

BASIS OF CONSOLIDATION
The Group financial  statements include and consolidate the financial statements
of Acambis plc and each of its subsidiary undertakings. Acquisitions made by the
Group are accounted for under the acquisition method of accounting and the Group
financial  statements include the results of such subsidiaries from the relevant
date of acquisition.  Intra-Group  transactions and profits are eliminated fully
on consolidation.

REVENUE

Group revenue  comprises the value of sales from products and income  (excluding
VAT and taxes,  trade  discounts  and  intra-Group  transactions)  derived  from
contract  research  fees and license fees  receivable  from third parties in the
normal course of business.  Revenue from product  sales is  recognized  when the
risks and rewards of ownership have been  transferred to the customer,  and when
the other conditions within paragraph 14 of IAS18 have been met. Where the Group
is  required to  undertake  R&D  activities  and the fee is  creditable  against
services provided by the Group, that revenue is deferred and recognized over the
period  over  which the  services  are  performed.  Contract  research  fees are
recognized  in the  accounting  period in which the related work is carried out.
Milestones receivable are recognized when they fall contractually due.

Profit is  recognized  on  long-term  contracts  when the final  outcome  can be
assessed  with  reasonable  certainty  by including  turnover and related  costs
within the  income  statement  as  contract  activity  progresses.  Turnover  is
recognized  according  to the  extent  of  performance  under the  contract.  In
determining  the degree of  contractual  performance,  reference  is made to the
costs incurred in relation to the total estimated expected costs. In determining
the degree of contractual  performance,  reference is made to the costs incurred
in relation to the total  estimated  expected costs as costs incurred are a fair
reflection of the services performed to date.

The smallpox vaccine contract with the CDC, awarded to Acambis in November 2001,
is a  fixed-fee  arrangement  requiring  the  delivery  of products as well as a
concurrent R&D program.  The two  transactions are linked in such a way that the
commercial  effect  cannot be  understood  without  reference  to the  series of
transactions  as a  whole.  In  accordance  with  IAS18,  this  arrangement  has
therefore  been treated as a single  long-term  contract whose elements have not
been accounted for separately.

Turnover and profits are recognized according to the extent of performance under
the  contract,  as  described  above.  Manufacturing  costs in  respect  of this
contract are deemed to be incurred when the risks and rewards of ownership  have
been transferred, as described above; R&D costs are recognized as incurred.

COST OF SALES
The Group  has  classified  manufacturing  costs  and  costs  that are  directly
attributable to funded research and vaccine manufacture as cost of sales.

RESEARCH AND DEVELOPMENT COSTS
Research  costs are  expensed  as  incurred.  Internally  generated  expenditure
arising from development (or from the development  phase of an internal project)
is  capitalized  if, and only if, it satisfies all of six specified  criteria in
IAS38 'Intangible assets'. It is management's opinion that it is not possible to
satisfy the requirement to demonstrate  the technical  feasibility of a project,
and  that it will  generate  probable  future  economic  benefits,  until  final
submission for regulatory approval has been obtained.

SHARE-BASED PAYMENT TRANSACTIONS
Employees  (including  Directors) of the Group may receive some  remuneration in
the form of share-based payment transactions,  whereby employees render services
in exchange for shares or rights over shares (equity-settled transactions).

The cost of equity-settled  transactions with employees is measured by reference
to the  fair  value  at the  date at  which  they  are  granted.  Fair  value is
determined  in  conjunction  with an external  valuer,  using a binomial  option
pricing  model for the SAYE  Scheme and the ESPP.  The fair value of awards made
under the 1996  Acambis  Share Option  Scheme (the 1996 Plan),  the 1999 Acambis
Share  Option  Plan (the 1999  Plan) and the LTIP is  measured  using a binomial
option  pricing  model  adjusted  to reflect  the TSR  market-based  performance
condition.  For all  options  and  awards  with a TSR  market-based  performance
condition the pricing model used follows  similar  principles to the Monte Carlo
approach to value the award and takes into account the fact that TSR vesting and
share price performance are not independent.

The  cost  of  equity-settled  transactions  is  recognized,   together  with  a
corresponding  increase  in  equity,  over  the year in  which  the  performance
conditions  are  fulfilled,  ending on the date on which the relevant  employees
become  fully  entitled to the award  (vesting  date).  The  cumulative  expense
recognized  for  equity-settled  transactions  at each  reporting date until the
vesting date reflects the extent to which the vesting period has expired and the
number of awards that, in the opinion of the Directors,  will  ultimately  vest.
The cost is allocated to R&D costs, sales and marketing costs and administration
costs on the basis of headcount.

No expense is  recognized  for awards that do not  ultimately  vest,  except for
awards where vesting is conditional upon a market  condition.  These are treated
as vesting,  irrespective  of whether or not the market  condition is satisfied,
provided that all other performance conditions are satisfied.

The dilutive  effect of  outstanding  options is reflected as  additional  share
dilution in the  computation  of earnings  per share.  The Group has an employee
share   incentive  plan  and  an  employee  share  trust  for  the  granting  of
non-transferable options to executives and senior employees. Shares in the Group
held by the employee share trust are treated as treasury shares and presented in
the balance sheet as a deduction from equity.

The Group has taken  advantage of the  transitional  provisions  of IFRS2 'Share
based payments' in respect of  equity-settled  awards and has applied IFRS2 only
to  equity-settled  awards  granted after 7 November 2002 that had not vested on
December 31, 2004.

TAXATION
The tax expense  represents  the sum of the tax  currently  payable and deferred
tax, including UK corporation tax and foreign tax.

The tax  currently  payable  is based on taxable  profit  for the year.  Taxable
profit  differs from net profit as reported in the income  statement  because it
excludes  items of income or expense  that are  taxable or  deductible  in other
years and it further  excludes items that are never taxable or  deductible.  The
Group's  liability for current tax is calculated  using tax rates that have been
enacted or substantively enacted by the balance sheet date.

Deferred income tax is provided,  using the liability  method,  on all temporary
differences  at the  balance  sheet  date  between  the tax bases of assets  and
liabilities and their carrying amounts for financial reporting purposes.

Deferred  income tax assets and  liabilities  are  recognized for all deductible
temporary differences, carry-forward of unused tax losses, to the extent that it
is probable that taxable  profit will be available  against which the deductible
temporary differences, carry-forward of unused tax losses can be utilized:
-    except where the deferred income tax asset or liability relating to the
     deductible temporary difference arises from the initial recognition of an
     asset or liability in a transaction that is not a business combination and,
     at the time of the transaction, affects neither the accounting profit nor
     taxable profit or loss; and
-    in respect of deductible temporary differences associated with investments
     in subsidiaries, associates and interests in joint ventures, deferred tax
     assets or liabilities are only recognized to the extent that it is probable
     that the temporary differences will reverse in the foreseeable future and
     taxable profit will be available against which the temporary difference can
     be utilized.

In the UK and the US, the Group is  entitled to a tax  deduction  for the amount
treated as compensation on exercise of certain employee share options under each
jurisdiction's tax rules. As explained under 'Share-based payment  transactions'
above, a compensation  expense is recorded in the Group's income  statement over
the period from the grant date to the vesting date of the relevant  options.  As
there is a temporary difference between the accounting and tax bases, a deferred
tax asset is recorded. The deferred tax asset arising is calculated by comparing
the estimated amount of tax deduction to be obtained in the future (based on the
Acambis plc share price at the balance sheet date) with the cumulative amount of
the  compensation  expense  recorded in the income  statement.  If the amount of
estimated future tax deduction exceeds the cumulative amount of the remuneration
expense at the  statutory tax rate,  the excess is recorded  directly in equity,
against the profit and loss reserve.

No  compensation  charge is  recorded  in respect of  options  granted  before 7
November 2002 or in respect of those  options which have been  exercised or have
lapsed before  December 31, 2004.  Nevertheless,  tax deductions have arisen and
will continue to arise on these options.

The tax effects  arising in relation to these  options are recorded  directly in
equity, against the profit and loss reserve.

The  carrying  amount of deferred  income tax assets is reviewed at each balance
sheet  date  and  reduced  to the  extent  that it is no  longer  probable  that
sufficient taxable profit will be available to allow all or part of the deferred
income tax asset to be utilized.

Deferred  income tax assets and  liabilities  are measured at the tax rates that
apply to the period  when the asset is  realized  or the  liability  is settled,
based on tax rates  (and tax  laws)  that have  been  enacted  or  substantively
enacted at the balance  sheet  date.  Income tax  relating  to items  recognized
directly in equity is recognized in equity and not in the income statement.

GOODWILL
Goodwill on acquisition is initially  measured at cost,  being the excess of the
cost of the business  combination  over the acquirer's  interest in the net fair
value of the identifiable assets,  liabilities and contingent  liabilities.  The
fair value of the consideration is determined by applying appropriate  discounts
to contingent and deferred consideration, to the level where the Group considers
those  liabilities will be payable.  Where the consideration for the acquisition
of a business  includes  non-interest  bearing cash payments due after more than
one year,  the  liability  is recorded at its present  value,  after  applying a
discount rate that  approximates to that which a lender would typically  require
for a similar  transaction,  and taking into account the  risk/likelihood of the
payment being made.

Where  revisions are made to the expected  amounts of  contingent  consideration
payable as a result of changes to  estimates,  such changes are accounted for at
the date of the change in estimate.

Following initial recognition, goodwill is not amortized but is measured at cost
less any  accumulated  impairment  losses.  Goodwill is reviewed for  impairment
annually or more frequently if events or changes in circumstances  indicate that
the carrying value may be impaired.

INTANGIBLE ASSETS
Separately  identifiable  intangible assets acquired are capitalized at cost and
those acquired from a business  acquisition  are capitalized at fair value as at
the date of  acquisition.  Following  initial  recognition,  the  cost  model is
applied.  The useful lives of these intangible  assets are assessed to be either
finite or indefinite. Where amortization is charged on assets with finite lives,
this expense is taken to the income  statement.  In the case of assets  acquired
relating to BPC this is through the 'Cost of sales' line item.

Intangible assets are tested for impairment when a trigger event occurs.  Useful
lives are also examined on an annual basis and  adjustments,  where  applicable,
are made on a  prospective  basis.  Useful  lives are as  follows:  Distribution
contract  - 88 months  Software  assets - 3 years  R&D  technology  -  Variable,
depending on technology

JOINT VENTURE UNDERTAKINGS
Investments  in joint  ventures  are  carried  in the  balance  sheet at cost as
adjusted by post  acquisition  changes in the Group's share of the net assets of
the  joint  ventures,  less  any  impairment  in the  value  of  the  individual
investments.  The Group's  share of net profits and losses of joint  ventures is
included in the income statement net of interest and tax.

PROPERTY, PLANT AND EQUIPMENT
Property,  plant and equipment is stated at cost less  accumulated  depreciation
and any impairment in value. Land is not depreciated. Depreciation is calculated
on a straight-line basis over the estimated useful life of the asset as follows:

_______________________________________________________________________________
Freehold buildings                         39 years
Leasehold buildings                        15 years or term of lease if shorter
Laboratory and manufacturing equipment     4 to 7 years
Office equipment                           3 to 5 years
_______________________________________________________________________________

The carrying values of property, plant and equipment are reviewed for impairment
when events or changes in  circumstances  indicate the carrying value may not be
recoverable.  If any such indication exists and where the carrying values exceed
the  estimated  recoverable  amount,  the  assets or  cash-generating  units are
written down to their recoverable  amount.  The recoverable  amount of property,
plant and  equipment  is the greater of net  selling  price and value in use. In
assessing value in use, the estimated  future cash flows are discounted to their
present  value  using a pre-tax  discount  rate  that  reflects  current  market
assessments of the time value of money and the risks specific to the asset.

For an asset  that does not  generate  largely  independent  cash  inflows,  the
recoverable amount is determined for the cash-generating unit to which the asset
belongs. Impairment losses are recognized in the income statement.

An item of property,  plant and equipment is de-recognized upon disposal or when
no future economic  benefits are expected to arise from the continued use of the
asset. Any gain or loss arising on  de-recognition  of the asset  (calculated as
the difference  between the net disposal proceeds and the carrying amount of the
item) is included in the income statement in the year the item is derecognized.

The Group does not capitalize  interest charges on loans to fund the purchase of
tangible fixed assets.

INVESTMENTS
Investments in subsidiaries are shown at cost less any provision for impairment.
Available-for-sale  investments are recorded at fair value.  Unrealized  holding
gains and any temporary  unrealized holding losses after the initial recognition
are reflected  through  reserves,  net of related taxes.  Impairment  losses and
realized gains and losses are reported in the income statement.

RECOVERABLE AMOUNT OF NON-CURRENT ASSETS

At each reporting date, the Group assesses  whether there is any indication that
an asset may be impaired.  Where an indicator of  impairment  exists,  the Group
makes a formal estimate of recoverable  amount.  Where the carrying amount of an
asset exceeds its  recoverable  amount the asset is  considered  impaired and is
written down to its recoverable  amount.  Recoverable amount is the higher of an
asset's or cash-generating unit's fair value less costs to sell and its value in
use and is  determined  for an  individual  asset,  unless  the  asset  does not
generate cash inflows that are largely independent of those from other assets or
groups of assets.

INVENTORIES, EXCLUDING LONG-TERM CONTRACTS
Inventories  are  valued at the lower of cost and net  realizable  value.  Costs
incurred in bringing  each  product to its present  location and  condition  are
accounted for as follows:

________________________________________________________________________________
Raw materials                                 purchase cost on a first-in,
                                              first-out basis
________________________________________________________________________________
Finished goods and work in progress           cost of direct materials and labor
                                              and a proportion of manufacturing
                                              overheads based on normal
                                              operating capacity but excluding
                                              borrowing costs.
________________________________________________________________________________


Net realizable  value is the estimated  selling price in the ordinary  course of
business,  less estimated  costs of completion and the estimated costs necessary
to make the sale.

The Group assesses at each  reporting  date whether there is an indication  that
inventory may be impaired, or if the estimate of the net realisable value of the
inventory is lower than the carrying value. Inventory is valued at the lower of
its cost and its net realisable  value,  and any write down is recognised in the
income statement.

FINANCIAL INSTRUMENTS

From time to time, the Group uses derivative  financial  instruments in the form
of sterling and foreign  currency  contracts to hedge its risks  associated with
foreign currency fluctuations and those in the form of yield-enhancing  deposits
to maximize interest rates. Such derivative financial  instruments are stated at
fair value with  movements in fair value recorded in the income  statement.  The
fair value of forward  exchange  contracts is calculated by reference to current
forward exchange rates for contracts with similar maturity profiles.

The Group makes  certain  deposits in foreign  currencies  for fixed terms (dual
currency  deposits)  which,  at the option of the bank,  mature in that  foreign
currency or are converted to another currency at a pre-agreed exchange rate. The
Group considers that such arrangements  contain an embedded  derivative element,
which is  separated  from the host  contract and  accounted  for as a derivative
financial  instrument  under IAS39  'Recognition  and  measurement  of financial
instruments'.  This is  initially  stated in the  balance  sheet at cost.  After
initial  recognition,  it is measured at fair value with movements in fair value
recorded in the income statement.

A gain or loss arising  from a change in the fair value of a financial  asset or
financial  liability  classified  as at fair value through the profit or loss is
recognized in the income statements.

CASH AND CASH EQUIVALENTS

Cash  and cash  equivalents  comprise  cash at bank  and in hand and  short-term
deposits with an original maturity of three months or less.

BORROWING COSTS
Borrowing costs are recognized as an expense when incurred.

ACCOUNTING FOR DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES
Derivatives  are  initially  accounted  and measured at fair value on the date a
derivative contract is entered into and subsequently measured at fair value. The
gain or loss on re-measurement is taken to the income statement except where the
derivative  is  a  designated  cash-flow  hedging  instrument.   The  accounting
treatment of  derivatives  classified  as hedges  depends on their  designation,
which occurs on the date on which a  commitment  to the  derivative  contract is
made.

The Group designates derivatives as:
-  A hedge of the fair value of an asset or liability (fair value hedge);
-  A hedge of the income/cost of a highly probable forecasted transaction or
   commitment (cash flow hedge); or
-  A hedge of a net investment in a foreign entity.

In order to qualify for hedge  accounting,  the Group is required to document in
advance  the  relationship  between  the  item  being  hedged  and  the  hedging
instrument. The Group is also required to document and demonstrate an assessment
of the relationship  between the hedged item and the hedging  instrument,  which
shows that the hedge will be highly effective on an ongoing basis.

This effectiveness testing is re-performed at each period end to ensure that the
hedge remains  highly  effective.  Gains or losses on fair value hedges that are
regarded as highly  effective are recorded in the income statement with the gain
or loss on the hedged item attributable to the hedged risk.

Gains or losses on cash flow hedges that are  regarded as highly  effective  are
recognized  in equity.  Where the  forecast  transaction  results in a financial
asset or  liability  only gains or losses  previously  recognized  in equity are
reclassified  to  profit or loss in the same  period  as the asset or  liability
affects profit or loss. Where the forecasted  transaction or commitment  results
in a non-financial  asset or liability,  any gains or losses previously deferred
in equity are  included in the cost of the related  asset or  liability.  If the
forecasted  transaction or commitment  results in future income or  expenditure,
gains or losses  deferred in equity are  transferred to the income  statement in
the same  period  as the  underlying  income  or  expenditure.  The  ineffective
portions of the gain or loss on the hedging  instrument are recognized in profit
or loss. For the portion of hedges deemed  ineffective or  transactions  that do
not  qualify  for  hedge  accounting  under  IAS39,  any  change  in  assets  or
liabilities is recognized immediately in the income statement.  Where a hedge no
longer meets the effectiveness  criteria, any gains or losses deferred in equity
are only  transferred  to the income  statement when the committed or forecasted
transaction  is recognized  in the income  statement.  However,  where an entity
applied cash flow hedge  accounting  for a forecasted  or committed  transaction
that is no longer  expected to occur,  then the cumulative gain or loss that has
been recorded in equity is transferred to the income  statement.  When a hedging
instrument expires or is sold, any cumulative gain or loss existing in equity at
the time remains in equity and is recognized  when the forecast  transaction  is
ultimately recognized in the income statement.

LEASES
Finance leases, which transfer to the Group the risks and benefits incidental to
ownership of the leased item,  are  capitalized at the inception of the lease at
the fair value of the leased  property or, if lower, at the present value of the
minimum  lease  payments.  Lease  payments are  apportioned  between the finance
charges and reduction of the lease liability so as to achieve a constant rate of
interest on the remaining balance of the liability.  Finance charges are charged
directly against income.

Where the Group enters into transactions  which meet the criteria for a sale and
finance  leaseback,  the difference  between the sale price of the asset and its
previous carrying value is deferred and amortized over the lease term.

Capitalized  leased  assets are  depreciated  over the shorter of the  estimated
useful life of the asset or the lease term.  Leases where the lessor retains the
risks and benefits of ownership of the asset are classified as operating leases.

Operating lease payments are recognized as an expense in the income statement on
a straight-line basis over the lease term.

PROVISIONS
Provisions  are  recognized  when the Group has a present  obligation  (legal or
constructive)  as a result of a past event,  it is  probable  that costs will be
required to be incurred to settle the obligation and a reliable  estimate can be
made of the amount of the  obligation.  Legal fees  associated  with  litigation
arising as a result of  circumstances in existence at the balance sheet date are
provided for based on management's best estimate of costs to be incurred.

FOREIGN CURRENCY AND TRANSLATION
Transactions  denominated  in foreign  currencies are recorded in the functional
currency  of the Group  entity at  actual  exchange  rates as at the date of the
transaction.  Monetary assets and liabilities  denominated in foreign currencies
are  translated at the rates ruling at the balance sheet date.  All  differences
are taken to the income statement except where financing of a foreign subsidiary
through  long-term  loans and  deferred  trading  balances  is intended to be as
permanent as equity,  such loans and inter-Company  balances are treated as part
of the net investment and, as such, any exchange  differences  arising are dealt
with as adjustments to reserves.

Assets and liabilities of overseas subsidiary and joint venture undertakings are
translated  into sterling at rates of exchange ruling at the balance sheet date.
The results and cash flows of overseas subsidiary and joint venture undertakings
are  translated  into  sterling  using  average  rates  of  exchange.   Exchange
adjustments  arising  when the  opening  net assets and the profits for the year
retained by overseas  subsidiary and joint venture  undertakings  are translated
into  sterling are taken  directly to equity.  On disposal of a foreign  entity,
accumulated  exchange  differences  are recognized in the income  statement as a
component of the gain or loss on disposal.

Goodwill  and fair value  adjustments  arising on the  acquisition  of a foreign
entity are treated as assets and  liabilities  of the acquiring  company and are
recorded  at the  exchange  rate at the date of the  transaction.  The Group has
taken advantage of the provisions  under IFRS1,  and does not have to apply this
to acquisitions made before August 2003.

ESOP TRUST
Acambis plc recognizes  the assets and  liabilities of the ESOP trust in its own
accounts  and shares held by the trust are  recorded  at cost as a deduction  in
arriving   at   shareholders'   funds   until  such  time  as  the  shares  vest
unconditionally  to  employees.  The trust is a separately  administered  trust,
funded by loans from Acambis plc, whose assets comprise shares in Acambis plc.

FUTURE PRONOUNCEMENTS
At the date of approval of these  financial  statements the following  standards
and  interpretations  which have not been applied in these financial  statements
were in issue but not yet effective:

-  an amendment to IAS21 'The effects of changes in foreign exchange rates' in
   respect of an entity's investment in foreign operations;
-  an amendment to IAS1 'Presentation of financial statements' requiring new
   disclosures about entities' management of their capital resources;
-  amendments to IAS39 and IFRS4 'Insurance contracts' which clarify whether
   financial guarantees fall within the scope of IAS39 or IFRS4 and stipulate
   the measurement method to be applied to such guarantees;
-  an amendment to IAS39 to permit hedge accounting for certain forecast
   intra-Group transactions; and
-  a new accounting standard, IFRS7 'Financial instruments: Disclosures'. This
   standard replaces IAS30 'Disclosures in the financial statements of banks and
   similar institutions' and the disclosure requirements in IAS32 'Financial
   instruments: disclosure and presentation' and locates in one place all
   disclosures relating to financial instruments. The new requirements
   incorporate many of IAS32's disclosures as well as additional qualitative and
   quantitative disclosures on the risks arising from financial instruments.

The Directors believe the adoption of these standards and interpretations in the
future  periods will have no material  impact on the financial  statements  when
they come into effect for periods after January 1, 2006.

2     SEGMENTAL INFORMATION

The Group's  primary  reporting  format is business  segments and its  secondary
format is geographic  segments.  At December  2005,  the Group is organized on a
worldwide basis in one business  segment of vaccines,  and into two geographical
areas of Europe and North America.  Transfer prices between  segments are set on
an arm's length basis in a manner  similar to  transactions  with third parties.
The Group's geographical segments are determined by location of operations.

GEOGRAPHICAL SEGMENT
The following table presents  revenue and certain asset and capital  expenditure
information regarding the Group's geographic segments.

                                   Europe       North America      Total Group
_______________________________________________________________________________
                           2005      2004   2005         2004    2005     2004
                           GBPm      GBPm   GBPm         GBPm    GBPm     GBPm
_______________________________________________________________________________
Revenue:
Sales to external           1.8       8.5   39.1         77.0    40.9     85.5
customers
Other segment
information:
Total assets               79.3     104.0   54.1         59.9   133.4    163.9
_______________________________________________________________________________
Total assets               79.3     104.0   54.1         59.9   133.4    163.9
_______________________________________________________________________________
Capital additions:
Tangible fixed assets           -         -  5.2          3.1     5.2      3.1
Intangible assets               -         -  0.6          0.2     0.6      0.2
_______________________________________________________________________________

3   INCOME AND EXPENSES

i) OTHER INCOME

In May 2005, the Group sold  information and rights of a previous R&D project in
exchange for shares,  valued at GBP0.4m at the time.  The shares are held on the
balance sheet as a financial asset (see note11).  In May 2004, the Group reached
a c. GBP10.6m ($19m) agreement with Baxter to terminate the Canton manufacturing
agreement  under  which  Baxter was to place  manufacturing  orders at  Acambis'
Canton facility. The first GBP5.1m ($9m) was received in May 2004 and the second
installment  of GBP2.6m ($5m) was received in January 2005.  The third and final
installment of GBP2.9m ($5m) was received in January 2006. The Group  discounted
future  cash  receipts  and, as a result,  recorded  other  operating  income of
GBP10.2m in 2004. In 2005 GBP0.2m (2004 - GBP0.2m) was recorded  within  finance
income (see (iii) below), reflecting the staged payment nature of the agreement.

ii) ADMINISTRATION COSTS


                                                             2005   2004
                                                             GBPm   GBPm
________________________________________________________________________
Administration costs                                          7.7    2.9
Canton plant impairment                                         -    1.9
Restructuring costs                                             -    0.7
________________________________________________________________________
Total administration costs                                    7.7    5.5
________________________________________________________________________

iii) FINANCE INCOME
                                                             2005   2004
                                                             GBPm   GBPm
________________________________________________________________________
Unwinding of discounts in relation to deferred debtors        0.2    0.2
Interest receivable                                           3.8    4.6
________________________________________________________________________
Total finance income                                          4.0    4.8
________________________________________________________________________

iv) FINANCE COSTS
                                                             2005   2004
                                                             GBPm   GBPm
________________________________________________________________________
On bank overdrafts                                            0.2    0.1
Interest element of finance leases                            0.6    0.7
Unwinding of discounts in relation to contingent and
deferred consideration                                        0.2    0.1
________________________________________________________________________
Total finance costs                                           1.0    0.9
________________________________________________________________________

v) STAFF COSTS
                                                             2005   2004
                                                             GBPm   GBPm
________________________________________________________________________
Wages and salaries                                           14.4   14.5
Social security costs                                         1.1    1.4
Other pension and 401k costs                                  0.4    0.4
Cost of share-based payments                                  0.8    0.7
________________________________________________________________________
Total employee benefits                                      16.7   17.0
________________________________________________________________________

During 2004, a third-party  company to which the Group  provided  administrative
services paid a share of the Group's administrative costs, including GBP0.2m for
staff costs. This arrangement ceased in 2004 and these costs are included in the
comparative figures shown above only.

The average  monthly number of employees  during the year  (including  Executive
Directors) was:

                                            UK        US     2005    2004
                                        Number    Number   Number  Number
_________________________________________________________________________
Research and development                     8        93      101     118
Sales and marketing                          3        19       22      19
Manufacturing                                -        90       90      87
Administration                              19        43       62      65
_________________________________________________________________________
                                            30       245      275     289
_________________________________________________________________________

At December 31, 2005, the Group had 285 employees (2004 - 270).


4   OPERATING (LOSS)/PROFIT

The following items are included in operating (loss)/profit:

                                             2005         2004
                                             GBPm         GBPm
______________________________________________________________
Depreciation of fixed assets:
- owned                                       3.1          2.7
- held under finance leases                   1.9          1.9
Cost of share-based payments (note 24)        0.8          0.7
Amounts paid to the Group's Auditors (see
below)                                        0.5          0.5
Operating lease charges for plant and
equipment                                     0.1          0.1
Operating lease charges for property          2.2          1.8
Loss on disposal of fixed assets              0.1          0.1
Repairs and maintenance costs for property,
plant and equipment                           0.5          0.4
Exchange (loss)/gain on foreign currency
borrowings                                   (0.4)         0.3
Cost of inventories recognized as expenses    3.0         17.9
Amortization of intangibles in cost of
sales                                         0.7          0.7
Amortization of intangibles in operating
expenses                                      0.2          0.1
______________________________________________________________

During the year the Group obtained the following services from the Group's
Auditors:

                                             2005         2004
                                             GBPm         GBPm
______________________________________________________________
Audit services:
- statutory audit                             0.2          0.1
- related regulatory reporting                0.1          0.1
Tax services:
- compliance services                         0.1          0.1
- advisory services                           0.1          0.2
______________________________________________________________
                                              0.5          0.5
______________________________________________________________

5   INCOME TAX

Tax is charged on profits made in the country where each Group company is based.
Major components of income tax expense for the year are as follows:

Analysis of (credit)/charge in the            2005       2004
consolidated income statement                 GBPm       GBPm
______________________________________________________________
Current income tax                            (0.3)       4.2
Deferred taxation                             (0.4)       3.1
______________________________________________________________
Income tax (benefit)/expense in the
consolidated income statement                 (0.7)        7.3
______________________________________________________________

Tax on items charged to equity
______________________________________________________________
Current income tax credit on employee share
schemes                                          -        (1.2)
Deferred tax on revaluation of
available-for-sale investment                  0.1           -
______________________________________________________________
Income tax expense/(benefit) reported in
equity                                         0.1        (1.2)
______________________________________________________________

A reconciliation of income tax expense applicable to accounting profit before
tax at the statutory income tax rate to total taxation for the Group is as
follows:

                                               2005       2004
                                               GBPm       GBPm
______________________________________________________________
(Loss)/profit before tax                      (27.7)      27.0

At the standard rate of corporation tax in
the UK of 30% (2004 - 30%)                     (8.3)       8.1
Effects of:
Utilization of tax losses                      (2.9)      (3.6)
Losses carried forward                         13.7          -
Expenses not deductible for tax purposes        0.2       (1.1)
Adjustments in respect of foreign tax rates    (3.5)       0.2
Other timing differences                       (0.5)       3.7
Adjustments to tax in respect of prior period   0.6          -
______________________________________________________________
Total taxation                                 (0.7)       7.3
______________________________________________________________

Movements in the deferred tax account are as follows:

                                        Deferred tax             Deferred tax
                                               asset                liability
                                         2005   2004       2005          2004
                                         GBPm   GBPm       GBPm          GBPm
_______________________________________________________________________________
At January 1,                               -    2.1       (1.7)         (1.8)
Accelerated capital allowances            0.3      -          -          (2.7)
Short-term timing differences               -      -          -           2.6
Exchange differences                        -      -        0.2           0.2
Available-for-sale investment               -      -       (0.2)            -
Tax losses                                  -   (2.1)         -             -
_______________________________________________________________________________
At December 31,                           0.3      -       (1.7)         (1.7)
_______________________________________________________________________________

No deferred tax is recognized on the un-remitted earnings of overseas
subsidiaries and joint ventures. The Directors have determined that, as earnings
are continually reinvested by the Group, undistributed earnings of the
subsidiaries and joint ventures will not be distributed in the foreseeable
future.

Deferred tax assets and liabilities are only offset where there is a legally
enforceable right of offset and there is an intention to settle the balances
net. No balances have been offset in the current or previous years.

UNRECOGNIZED DEFERRED TAX ASSETS/(LIABILITIES)

                                               2005       2004
                                               GBPm       GBPm
______________________________________________________________
Tax losses                                      7.9        0.6
R&D tax credit                                  0.7          -
Short-term timing differences                  (0.6)         -
Other                                           0.4          -
______________________________________________________________
At December 31,                                 8.4        0.6
______________________________________________________________

Deferred tax assets have not been  recognized  in respect of tax losses  because
there is  uncertainty  in the  probability  that they will be recoverable in the
foreseeable future.

6   EARNINGS PER ORDINARY SHARE (BASIC AND FULLY DILUTED)

Basic EPS is  calculated  by  dividing  the  earnings  attributable  to ordinary
shareholders  by the weighted  average number of ordinary shares in issue during
the year,  excluding those held in the employee share trust (see note 23), which
are  treated  as  cancelled  until  the  shares  vest  unconditionally  with the
employees.

For fully diluted EPS, the weighted  average number of ordinary  shares in issue
is adjusted to assume conversion of dilutive potential ordinary shares.

The  Group's  potentially  dilutive  securities  consist  of share  options  and
performance shares.

For basic and diluted EPS, the  weighted  average  numbers of shares used in the
calculations are set out below:


                                                    2005                   2004
_______________________________________________________________________________
                                                Weighted               Weighted
                                                 average                average
                                   Earnings       number Earnings        number
                                       GBPm    of shares     GBPm     of shares
_______________________________________________________________________________
Basic EPS
(Loss)/earnings attributable to
ordinary shareholders                 (27.0) 107,211,367     19.7   106,300,080
Effect of dilutive securities:
Options                                   -            -        -     2,349,309
_______________________________________________________________________________
Adjusted (loss)/earnings              (27.0) 107,211,367     19.7   108,649,389
_______________________________________________________________________________

                                               2005       2004
______________________________________________________________
                                                Per        Per
                                              share      share
                                             amount     amount
                                              pence      pence
______________________________________________________________
Basic EPS
(Loss)/earnings attributable to
ordinary shareholders                         (25.2)      18.5
Effect of dilutive securities:
Options                                           -       (0.4)
______________________________________________________________
Diluted EPS                                   (25.2)      18.1
______________________________________________________________


7   GOODWILL

Cost                                                                 GPBm
At January 1, 2005                                                   21.0
Adjustment to contingent consideration                               (0.8)
Exchange movement                                                     0.3
_________________________________________________________________________
At December 31, 2005                                                 20.5
Amortisation at January 1, and December 31, 2005                      5.6
_________________________________________________________________________
Net book value at December 31, 2005                                  14.9
Net book value at December 31, 2004                                  15.4
_________________________________________________________________________

Goodwill  arose when Acambis Inc. was acquired in 1999 and when BPC was acquired
in August 2003.

In 2003, the Group acquired BPC for $6.5m (GBP4.0m) cash,  $2.0m (c. GBP1.1m) of
deferred  consideration  and $3.2m (c.  GBP1.8m)  of  contingent  consideration.
During 2005, deferred  consideration of $1.6m (GBP0.9m) (2004 - $0.6m (GBP0.3m))
and contingent  consideration  of $1.5m (GBP0.8m)  (2004 - $0.9m  (GBP0.5m)) was
paid.  During  2005,  the  conditions  for the payment of the  remainder  of the
contingent  consideration  were not met and $1.3m  (GBP0.7m) (2004 - GBPnil) was
deducted from the purchase price.

IMPAIRMENT TESTING OF GOODWILL
Goodwill  acquired  through  business  combinations  has been  allocated  to the
business as a whole.  Acambis  operates as a global  business  and does not have
cash-generating units at a level lower than the Group as a whole.

During the year, the goodwill has been tested for impairment in accordance  with
IAS36 'Impairment of assets'.  The recoverable value, which is the higher of the
Group's net selling price and its value in use, has been calculated based on the
market capitalization of the Group. No impairment charges were made.

8   OTHER INTANGIBLE ASSETS
                                Distribution     Software         R&D
                                    contract       assets   technology   Total
                                        GBPm         GBPm         GBPm    GBPm
_______________________________________________________________________________
Cost
At January 1, 2005                       4.7          0.6            -     5.3
Additions                                  -          0.2          0.4     0.6
Exchange movement                        0.5            -            -     0.5
_______________________________________________________________________________
At December 31, 2005                     5.2          0.8          0.4     6.4
_______________________________________________________________________________
Amortization
At January 1, 2005                       0.9          0.3            -     1.2
Charge for year                          0.7          0.2            -     0.9
Exchange movement                        0.1            -            -     0.1
_______________________________________________________________________________
At December 31, 2005                     1.7          0.5            -     2.2
Net book value at December 31,
2005                                     3.5          0.3          0.4     4.2
_______________________________________________________________________________
At January 1, 2004                       5.0          0.4            -     5.4
Additions                                  -          0.2            -     0.2
Exchange movement                       (0.3)           -            -    (0.3)
_______________________________________________________________________________
At December 31, 2004                     4.7          0.6            -     5.3
_______________________________________________________________________________
Amortization
At January 1, 2004                       0.2          0.2            -     0.4
Charge for year                          0.7          0.1            -     0.8
_______________________________________________________________________________
At December 31, 2004                     0.9          0.3            -     1.2
_______________________________________________________________________________
Net book value at December 31,
2004                                     3.8          0.3            -     4.1
_______________________________________________________________________________


9   PROPERTY, PLANT AND EQUIPMENT

                                                Manufacturing
                          Freehold        Short           and
                          land and    leasehold    laboratory   Office
                         buildings improvements     equipment equipment   Total
_______________________________________________________________________________
                              GBPm         GBPm          GBPm      GBPm    GBPm
_______________________________________________________________________________
Cost
January 1, 2005                0.6         20.4           6.8       2.6    30.4
Additions                        -          3.6           0.9       0.7     5.2
Disposals                        -            -             -      (0.3)   (0.3)
Exchange movement                -          2.5           1.3       0.4     4.2
_______________________________________________________________________________
At December 31, 2005           0.6         26.5           9.0       3.4    39.5
_______________________________________________________________________________
Depreciation
At January 1, 2005               -          8.6           2.0       1.3    11.9
Charge for year                  -          3.1           1.2       0.7     5.0
Impairment                       -          0.9             -         -     0.9
Disposals                        -            -             -      (0.2)   (0.2)
Exchange movement                -          1.1           0.7       0.3     2.1
_______________________________________________________________________________
At December 31, 2005             -         13.7           3.9       2.1    19.7
_______________________________________________________________________________
Net book value
_______________________________________________________________________________
At December 31, 2005           0.6         12.8           5.1       1.3    19.8
_______________________________________________________________________________
Net book value of assets
held under finance leases
included above:
At January 1, 2005               -          4.8           0.8         -     5.6
_______________________________________________________________________________
At December 31, 2005             -          3.5           0.7         -     4.2
_______________________________________________________________________________


                                                Manufacturing
                          Freehold        Short           and
                          land and    leasehold    laboratory   Office
                         buildings improvements     equipment equipment   Total
_______________________________________________________________________________
                              GBPm         GBPm          GBPm      GBPm    GBPm
_______________________________________________________________________________
Cost

January 1, 2004                0.6         20.3           8.4       2.1    31.4
Additions                        -          1.5           0.9       0.7     3.1
Disposals                        -         (0.2)         (1.8)        -    (2.0)
Exchange movement                -         (1.2)         (0.7)     (0.2)   (2.1)
_______________________________________________________________________________
At December 31, 2004           0.6         20.4           6.8       2.6    30.4
_______________________________________________________________________________
Depreciation
At January 1, 2004               -          5.2           2.0       0.7     7.9
Charge for year                  -          2.5           1.4       0.7     4.6
Impairment                       -          1.8           0.1         -     1.9
Disposals                        -         (0.3)         (1.2)        -    (1.5)
Exchange movement                -         (0.6)         (0.3)     (0.1)   (1.0)
_______________________________________________________________________________
At December 31, 2004             -          8.6           2.0       1.3    11.9
_______________________________________________________________________________
Net book value
At January 1, 2004             0.6         15.1           6.4       1.4    23.5
At December 2004               0.6         11.8           4.8       1.3    18.5
_______________________________________________________________________________

10  SUBSIDIARIES AND JOINT VENTURES

The  consolidated  financial  statements  include the  financial  statements  of
Acambis plc and the following subsidiaries:




                                                                        Country of        Parent
   Company name                                   Main business      incorporation       company   % owned
                                                                                           
__________________________________________________________________________________________________________
Acambis Research Limited           Corporate administration and  England and Wales   Acambis plc     100
                                                          sales
Acambis Inc.                       R&D, sales and manufacturing                 US   Acambis plc     100
Berna Products Corporation    Sales, marketing and distribution                 US   Acambis Inc.    100
Smallpox Biosecurity Limited                          Marketing  England and Wales   Acambis plc     100



JOINT VENTURE
As described in note 20, the Group has an interest in a Joint Venture. Since May
1999,  Acambis has  performed a  pre-agreed  work program on behalf of the Joint
Venture.  Costs  incurred  by the  Group on  behalf  of the  Joint  Venture  and
corresponding turnover received from the Joint Venture have been included in the
Group's financial statements.


11  FINANCIAL ASSETS: AVAILABLE-FOR-SALE INVESTMENTS


                                                              2005   2004
                                                              GBPm   GBPm
_________________________________________________________________________
At January 1,                                                    -      -
Additions                                                      0.4      -
Revaluation surplus transfer to equity (note 23)               0.2      -
_________________________________________________________________________
At December 31,                                                0.6      -
_________________________________________________________________________

In May 2005, the Group sold information and rights of a previous R&D project to
Cambridge Biostability Limited, an unquoted UK company, in exchange for
1,425,200 shares. The investment represents less than a 20% shareholding in that
company.

12  OTHER NON-CURRENT ASSETS

                                                              2005   2004
                                                              GBPm   GBPm
_________________________________________________________________________
Prepayments and accrued income                                     -  0.1
Settlement of Canton agreement                                     -  2.4
_________________________________________________________________________
                                                                   -  2.5
_________________________________________________________________________

The discounted interest rate used to value the Canton settlement receivable was
8.0%.
13  INVENTORY

                                                              2005   2004
                                                              GBPm   GBPm
_________________________________________________________________________
Raw materials                                                  0.4    0.4
Work in progress                                               0.5    2.7
Finished goods                                                 2.7    2.9
_________________________________________________________________________
                                                               3.6    6.0
_________________________________________________________________________

Inventory is stated net of a provision of GBP2.5m (2004 - GBP3.6m).The amount of
inventory write-down recognized as an expense in 2005 was GBP1.8m
(2004-GBP4.7m). This expense is included in the cost of sales line.

14  TRADE AND OTHER RECEIVABLES

                                                              2005   2004
                                                              GBPm   GBPm
_________________________________________________________________________
Trade receivables                                             12.4    8.2
Other receivables                                              0.5    0.7
Prepayments and accrued income                                 4.8    2.2
Settlement of Canton agreement                                 2.9    2.6
_________________________________________________________________________
                                                              20.6   13.7
_________________________________________________________________________

Trade receivables are non-interest-bearing and are generally on terms of 30 to
60 days. There was a provision against trade receivables of GBP0.1m at December
31, 2005 (2004 - GBPnil).

15  FINANCIAL INSTRUMENTS
The Group's financial  instruments comprise primarily cash and liquid resources,
a finance lease facility,  an overdraft  facility,  foreign currency  contracts,
short- and long-term debtors  receivable under the Canton settlement and various
items, such as trade debtors and trade creditors,  which arise directly from its
operations.  The main  purpose  of these  financial  instruments  is to  provide
working capital for the Group's operations.

The main risks  arising from the Group's  activities  and  involving  the use of
financial  instruments  are  foreign  currency  risk,  interest  rate  risk  and
liquidity risk. The Board reviews and agrees the Group's objectives and policies
for  managing  each of  these  risks.  Details  of the  Group's  objectives  and
policies,  both during the year and since the year-end, are set out below, along
with numerical  disclosures  for each category of financial  instrument.  Except
where indicated,  these  disclosures are indicative of the situation  throughout
the year.

FOREIGN CURRENCY RISK
The Group has  subsidiaries  that  operate and trade in the US,  with  revenues,
expenses and  financing  denominated  principally  in US dollars.  Through these
overseas  operations,  the Group is subject to foreign exchange risk,  including
the risk of fluctuations in the Group's net investment in, and reported  profits
from, foreign  subsidiaries when translated into sterling.  In addition,  the UK
trading subsidiary enters into contracts in a variety of foreign currencies.

The  Group  had  overall  surplus  cash  funds  throughout  the  year but had to
determine  in which  currency to hold cash  available  for  working  capital and
surplus funds.  This was done with reference to anticipated  future  expenditure
patterns and relative returns on funds held in different currencies. The Group's
current  policy is to hold surplus funds in sterling  over the long term,  which
currently  achieves a higher interest rate return whilst  mitigating the risk of
fluctuations in the Group's net assets, when reported in sterling.

From time to time,  the Group makes use of forward  contracts in order to reduce
uncertainty over the sterling value of anticipated US dollar  receipts,  thereby
reducing  uncertainty  over the level of the Group's  profits  when  reported in
sterling.  Typically,  in 2005 the Group took out  forward  contracts  for known
significant foreign currency  transactions only. There were no forward contracts
outstanding at the year-end.

During the year, the Group also used dual currency deposits for both euro and US
dollar deposits,  allowing an enhanced interest rate to be earned, which may, at
maturity,  be converted into sterling or dollars at the banks' discretion,  at a
rate previously agreed.  The Group had no dual currency deposits  outstanding at
the year-end.

Where Group  companies  have  monetary  assets and  liabilities  denominated  in
currencies other than their functional  currency,  these balances are translated
into that  subsidiary's  functional  currency.  With the  exception of gains and
losses on those  inter-Company  balances that are considered to be 'as permanent
as equity' and recorded in reserves,  foreign  exchange gains and losses arising
are  recorded  immediately  in  the  income  statement.  These  amounts  include
sterling-denominated   cash   balances   held  in  the  US,   US   dollar-   and
euro-denominated  balances  held  by  the  Company  and a US  dollar-denominated
overdraft  facility held by a UK  subsidiary.  In addition,  the Group has other
current  assets and  liabilities  denominated in foreign  currencies,  which the
Board does not consider to be significant.

LIQUIDITY RISK
The Board  monitors the level of cash and liquid  resources on a regular  basis,
and management monitors the level on a daily basis, to ensure that the Group has
sufficient  liquid funds to enable it to meet its  commitments as they fall due.
This is achieved through the production and review of cash forecasts,  including
sensitivity analyses. Approximately 60% of the Group's cash and liquid resources
are managed on a discretionary  basis by a third party within strict  parameters
that have been set by the Board.  The  remainder is invested in managed funds or
invested  in  bank  deposits  within  the  parameters  set by the  Board.  These
parameters  include  the  requirement  that the  institutions  used  must have a
minimum rating of Aa2 long-term or P-1 short-term, and a maximum investment with
any one counter-party of GBP20m.

INTEREST RATE RISK
The  Group  finances  its  operations  predominantly  through  cash  and  liquid
resources  generated through operating  activities,  from the issuance of equity
shares,  through  finance  leases and through an overdraft  facility.  It is the
Group's  policy to invest  surplus  cash on  deposit  or in money  market  funds
managed by professional  money  managers.  The performance of the investments is
reviewed by management on a regular  basis to ensure that  competitive  rates of
return are being achieved,  subject to the Board's  requirement  relating to the
accessibility  of funds and standing of financial  institutions  used. The Board
reviews  regularly  the  financing  facilities  available to the Group to ensure
competitive  rates of interest are being  obtained.  During the year,  the Group
invested in a cash  deposit  which  accrues  interest  dependent on the sterling
LIBOR rate.  This  deposit of GBP10.0m was  outstanding  at the year-end and was
valued at GBP10.0m (2004 - deposit GBP5.8m, valued at GBP5.7m).

The following table sets out the carrying value by maturity,  for each financial
instrument that is exposed to interest rate risk.

2005                                Within       One-two
                                  one year         years          Total
                                      GBPm          GBPm           GBPm
________________________________________________________________________
Floating rate:
Cash                                  11.0             -           11.0
________________________________________________________________________
Fixed rate:
Short-term deposits                   38.2             -           38.2
Liquid investments                     8.8          10.0           18.8
Obligations under finance leases      (7.1)            -           (7.1)
________________________________________________________________________


2004                                Within       One-two
                                  one year         years          Total
                                      GBPm          GBPm           GBPm
________________________________________________________________________
Floating rate
Cash                                  30.2             -           30.2
________________________________________________________________________
Fixed rate
Cash                                   0.7             -            0.7
Short-term deposits                   50.1             -           50.1
Liquid investments                    20.8             -           20.8
Obligations under finance leases      (3.1)         (6.3)          (9.4)
________________________________________________________________________

The Group's main customer is the US Government and therefore it assesses the
credit risk as low. There are no other significant concentrations of credit
risk.

FAIR VALUES OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES
There is no material difference between the book values and fair values of the
Group's financial assets and liabilities as at December 31, 2005. Fair values
have been calculated by discounting cash flows at prevailing interest rates.

                                                      2005     2004
                                                      GBPm     GBPm
___________________________________________________________________
Assets:
Foreign currency contracts                             0.1        -
___________________________________________________________________
Liabilities:
Foreign currency contracts                               -     (0.1)
___________________________________________________________________

In  accordance  with IAS39,  the Group has reviewed all  contracts  for embedded
derivatives that are required to be separately accounted for if they do not meet
certain  requirements  set out in the standard.  This  derivative is fair valued
based on discounted  future cash flows with gains and losses passing through the
income statement as hedge accounting is not available.

The Group has an embedded derivative deposit which accrues interest dependent on
UK LIBOR (the London interbank offered rate).

During the year, the Group also used dual currency deposits for both euro and US
dollar deposits,  allowing an enhanced interest rate to be earned, which may, at
maturity,  be converted into sterling or dollars at the banks' discretion,  at a
rate previously agreed.  The Group had no dual currency deposits  outstanding at
the year-end (2004 - none).

From time to time,  the Group makes use of forward  contracts in order to reduce
uncertainty over the sterling value of anticipated US dollar  receipts,  thereby
reducing  uncertainty  over the level of the Group's  profits  when  reported in
sterling.  Typically,  in 2005 the Group took out  forward  contracts  for known
significant   foreign  currency  only.  The  Group  had  no  forward   contracts
outstanding at the year-end  (2004 - a forward  contract to sell dollars and buy
sterling outstanding at the year-end).

16  CASH AND CASH EQUIVALENTS

                                                        2005      2004
                                                        GBPm      GBPm
______________________________________________________________________
Cash                                                    11.0      30.9
Short-term deposits                                     38.2      50.1
______________________________________________________________________
                                                        49.2      81.0
______________________________________________________________________

The weighted  average  interest  rate  received in the year was 3.9% for cash at
bank.  Short-term  deposits are made for varying  periods of between one day and
three months,  (the  weighted  average  maturity  being 14 days) and have earned
interest at 4.7%.

The Group had cash and liquid resources of GBP68.0m at December 31, 2005 (2004 -
GBP101.8m).  Of this  amount,  deposits  with an original  maturity of more than
three  months of  GBP18.8m  (2004 -  GBP20.8m)  have been  classified  as liquid
investments. The majority of these resources are invested in managed funds or on
bank deposit,  denominated in sterling, US dollars and euros.  Approximately 16%
of the  Group's  cash and liquid  resources  is  available  for use with a day's
notice (2004 - 30%),  with the remainder  being invested on deposits of up to 18
months.  The Group had  GBP0.7m of  restricted  cash on deposit at the  year-end
(2004 - GBP0.4m).

17  FINANCIAL LIABILITIES

                                                           2005      2004
                                                           GBPm      GBPm
_________________________________________________________________________
Current:
Short-term borrowings                                       4.0       3.6
_________________________________________________________________________
Short-term financial liabilities - obligations under
finance leases                                              7.1       3.1
_________________________________________________________________________
Other financial liabilities                                 0.1         -
_________________________________________________________________________
Derivative financial liabilities                              -       0.1
_________________________________________________________________________
                                                           11.2       6.8
_________________________________________________________________________
Non-current:
Other financial liabilities                                 1.6       6.3
_________________________________________________________________________

SHORT-TERM BORROWINGS

Under the terms of the agreement  between Acambis and Evans Vaccines  Limited (a
subsidiary of Chiron Corporation,  which has been acquired by Novartis AG) given
certain  conditions the obligation under the bank overdraft  facility of GBP4.0m
(2004 - GBP3.6m)  for part of the costs  incurred on the ARILVAX  project may be
repayable  within one year. The facility is underwritten  by Chiron.  Chiron has
granted to Acambis  100% of the  marketing  rights to ARILVAX in the US,  whilst
retaining  an option to buy back 50% of the profits  from the US sales in return
for  refunding  to Acambis the costs that  Acambis  has  incurred on the ARILVAX
program.  The overdraft facility was fully utilized at December 31, 2005 (2004 -
fully utilized) and was renewed in January 2006 for a further year.

During the year,  an  exchange  loss of  GBP0.4m  (2004 - gain of  GBP0.3m)  was
recorded in the income  statement,  resulting  from the  revaluation  of this US
dollar-denominated facility.

OBLIGATIONS UNDER FINANCE LEASES
The Group has a $40m (c.  GBP21m)  finance  lease  facility.  This was  arranged
through Baxter and was approved by  shareholders  in December 2001. In 2001, the
Group drew down $18.6m  (GBP14.0m) and has made no further  draw-downs  from the
facility.  The repayment schedule for the lease financing required that interest
only was repaid in 2003 and  capital and  interest  are  repayable  over 2004 to
2006.  The Group had an option to  repurchase  all of the  facility's  assets in
December  2003,  and on each  anniversary  thereafter,  for the capital  balance
outstanding at that time,  plus any accrued but unpaid interest due at the time,
and a make-whole  payment  (discounted  to present value) equal to the projected
future interest stream payable to the end of the lease term.

In December 2001, the Group committed to a finance lease,  repayable within five
years, relating to the purchase and  sale-and-leaseback of capital assets within
the manufacturing plant.

OTHER FINANCIAL LIABILITIES
In May 2005,  the Group  purchased a fill/finish  facility for  c.GBP1.8m  ($3m)
upfront and a further c. GBP2.6m ($4.5m) in equal installments  between 2006 and
2017. The balance relating to the discounted value of future payments is GBP1.7m
at  December  31, 2005 (2004 - GBPnil).  GBP0.1m is  included in 'current  other
financial  liabilities'  (2004 -  GBPnil),  and  GBP1.6m in  'non-current  other
financial liabilities' (2004 - GBPnil).

18  CURRENT LIABILITIES

TRADE AND OTHER PAYABLES


                                                          2005      2004
                                                          GBPm      GBPm
________________________________________________________________________
Trade payables                                            16.0       5.8
Other taxation and social security                         0.1       0.1
Other payables                                                 -     0.7
Deferred and contingent consideration                          -     1.7
________________________________________________________________________
                                                          16.1       8.3
________________________________________________________________________

19  PROVISIONS

In August 2005 BN filed legal actions  against  Acambis in the US in relation to
IP on its MVA smallpox vaccine.  A further suit was filed in Austria in February
2006. BN alleges use of trade secrets, misappropriation and patent infringement.
Acambis  strongly  believes  these  allegations  are without  foundation  and is
vigorously  defending  its  position.  A current  provision  of GBP2.3m  (2004 -
GBPnil) has been  recognized  in relation to future legal costs  relating to the
MVA litigation


20 INVESTMENT IN JOINT VENTURE

The Group has a 50% interest in the Pasteur  Merieux-OraVax  joint venture whose
principal business is to develop, manufacture, market and sell immunotherapeutic
and  preventative  vaccines  against H. pylori  infection  in humans.  The Joint
Venture represents  collaboration  between two partnerships,  Merieux-OraVax SNC
and OraVax-Merieux  Co.,  incorporated in Delaware,  US. These partnerships were
formed in March 1995 between the  companies now known as Acambis Inc. and sanofi
pasteur.  The Joint Venture trades under the name of Pasteur  Merieux-OraVax and
its accounting  year-end is December 31, The R&D budgets of the two partnerships
are  established  by joint  committees in which each of the parties has an equal
participation and role. The parties pay approximately equal shares of the agreed
budgets. The Joint Venture is being wound down.

The following  information is given in respect of the Group's share of the Joint
Venture:



                                                                   
                                                              2005       2004
                                                              GBPm       GBPm
_____________________________________________________________________________
Loss before tax                                                 -          -
Current assets                                                0.7        0.6
Liabilities due within one year                              (1.0)      (0.9)
_____________________________________________________________________________
                                                             (0.3)      (0.3)
_____________________________________________________________________________

Due to the nature of this Joint Venture as  collaboration  between two partners,
the following table provides an alternative analysis of the amounts shown above:

                                                            2005        2004
                                                            GBPm        GBPm
_____________________________________________________________________________

Share of cumulative amounts invested by the partners        17.0        15.2
Share of cumulative losses incurred by the Joint Venture   (17.3)      (15.5)
_____________________________________________________________________________
                                                            (0.3)       (0.3)
_____________________________________________________________________________

21       OTHER NON-CURRENT LIABILITIES

                                                             2005      2004
                                                             GBPm      GBPm
_____________________________________________________________________________

Deferred and contingent consideration                          -       0.5
_____________________________________________________________________________






22       CALLED-UP SHARE CAPITAL

                                                                                              
                                                                                2005                       2004
                                                                     Number    GBPm        Number          GBPm
                                                         ______________________________________________________

Authorized shares of 10p each
AT JANUARY 1, AND DECEMBER 31,                                  140,000,000     14.0   140,000,000         14.0
Allotted, called-up and fully paid ordinary shares of
10p each
At January 1,                                                   107,219,329     10.7   105,637,848         10.6
Exercise of share options                                           132,078        -     1,581,481          0.1
_______________________________________________________________________________________________________________
At December 31,                                                 107,351,407     10.7   107,219,329         10.7
_______________________________________________________________________________________________________________

All shares have equal voting rights.
As described in note 23, Acambis Employees Trustees Limited holds 84,972 shares,
which will be used to satisfy awards made under the LTIP. Consideration received
in 2005  through the  exercise  of share  options  amounted  to GBP0.2m  (2004 -
GBP1.9m).


23  STATEMENT OF CHANGES IN EQUITY

                                                              Share Share premium  Retained     Other
                                                            capital       account  earnings  reserves     Total
                                                               GBPm          GBPm      GBPm      GBPm      GBPm
_______________________________________________________________________________________________________________
At January 1, 2005                                             10.7          97.8       1.5     (2.5)     107.5
Gain on foreign currency exchange                                 -             -         -       1.6       1.6
_______________________________________________________________________________________________________________
Total income and expense recognized directly in equity            -             -         -       1.6       1.6
Loss for the year                                                 -             -    (27.0)         -    (27.0)
_______________________________________________________________________________________________________________
Total income and expense recognized                               -             -    (27.0)       1.6    (25.4)
Issue of new shares                                               -           0.2         -         -       0.2
Purchase of treasury shares                                       -             -     (0.2)         -     (0.2)
Revaluation of available-for-sale investment (net of              -             -       0.1         -       0.1
deferred tax)
Credit in respect of employee share schemes                       -             -       0.8         -       0.8
_______________________________________________________________________________________________________________

At December 31, 2005                                           10.7          98.0    (24.8)     (0.9)      83.0
_______________________________________________________________________________________________________________


                                                              Share Share premium  Retained     Other
                                                            capital       account  earnings  reserves     Total
                                                               GBPm          GBPm      GBPm      GBPm      GBPm
_______________________________________________________________________________________________________________
At January 1, 2004                                             10.6          96.0    (20.1)         -      86.5
Loss on foreign currency exchange                                 -             -         -     (2.5)     (2.5)
Deferred tax on share options                                     -             -       1.2         -       1.2
_______________________________________________________________________________________________________________
Total income and expense recognized directly in equity            -             -       1.2     (2.5)     (1.3)
Profit for the year                                               -             -      19.7         -      19.7
_______________________________________________________________________________________________________________
Total income and expense recognized                               -             -      20.9     (2.5)      18.4
Issue of new shares                                             0.1           1.8         -         -       1.9
Credit in respect of employee share schemes                       -             -       0.7         -       0.7
_______________________________________________________________________________________________________________
At December 31, 2004                                           10.7          97.8       1.5     (2.5)     107.5
_______________________________________________________________________________________________________________


The amount shown in 'other reserves' relates to foreign currency translation.

At December 31, 2005,  Acambis  Employees'  Trustees Limited held 84,972 (2004 -
62,190)  ordinary  shares in Acambis plc with a total  nominal value of GBP0.01m
(2004 - GBP0.01m). The cost of these shares of GBP0.2m (2004 - GBP0.1m) is shown
as a deduction to retained  earnings.  The total market value of these shares at
December 31, 2005 is GBP0.2m (2004 - GBP0.2m). All shares held by the Trust have
been  allocated  to  long-term  incentive  awards  and a charge has been made in
respect of all of these awards.  All costs relating to the administration of the
Trust are included within the accounts of Acambis plc as they arise.

24       SHARE-BASED PAYMENTS

SUMMARY OF SHARE SCHEMES IN OPERATION DURING THE YEAR

Acambis had the following  share-based  payment schemes in operation  during the
year.

1996 AND 1999 SCHEMES
The 1996  Scheme  and the 1999  Plan  involve  the grant of  market-value  share
options to participants.  The options are subject to a market-based  performance
condition  (Acambis' TSR performance  against a comparator  group).  The options
granted have a maximum contractual life of 10 years with the exception of the 15
October  2005 and 28 October  2003  options  granted to  employees  which have a
maximum contractual life of four years. For all options granted after January 1,
2004 (to  employees or Directors)  performance  is measured over three years and
there  is  no  retesting  of  the  performance  condition.  Further  information
regarding the operation of the scheme can be found in the remuneration report.

LTIP
The LTIP  involves  the grant of nil-cost  share  options to  participants.  The
options  are  subject to a  market-based  performance  condition  (Acambis'  TSR
performance  against a  comparator  group).  The options  granted have a maximum
contractual  life of three years and six months.  For all options  granted under
the LTIP  performance  is measured over three years and there is no retesting of
the performance  condition.  Further information  regarding the operation of the
scheme can be found in the remuneration report.

SAYE SCHEME
The SAYE Scheme is based on a three-year  monthly savings  contract and eligible
employees are granted  share  options with an exercise  price of up to 20% below
the share  price when the  invitation  is issued.  The  options  granted  have a
maximum  contractual life of three years and six months.  Vesting of the options
is not subject to the achievement of a performance target.

ESPP
The ESPP is based on a two-year monthly savings contract and eligible  employees
are granted share options with an exercise  price of up to a 15% discount to the
share  price at the time of  invitation.  The  options  granted  have a  maximum
contractual  life of two years and three  months.  Vesting of the options is not
subject to the achievement of a performance target.




Options outstanding under all schemes are as follows:
                                                                                              
                                                        January 1,                                   December 31,
                                                              2005   Granted  Exercised    Lapsed            2005
_________________________________________________________________________________________________________________
Scheme                                                        '000      '000       '000      '000            '000
1996                                                           233        36        (10)      (59)            200
1999                                                         3,173       806       (104)     (342)          3,533
SAYE                                                           105        38        (12)      (50)             81
ESPP                                                            85        50          -       (60)             75
1990 US(1)                                                     121         -          -      (107)             14
1995 US(2)                                                     155         -          -       (28)            127
_________________________________________________________________________________________________________________
Total                                                        3,872       930       (126)     (646)          4,030
_________________________________________________________________________________________________________________

                                                        January 1,                                   December 31,
                                                              2004   Granted  Exercised    Lapsed            2004
_________________________________________________________________________________________________________________
Scheme                                                        '000      '000       '000      '000            '000
1995                                                             5         -         (5         -               -
1996                                                           318        70       (113)      (42)            233
1999                                                         3,925       864     (1,277)     (339)          3,173
SAYE                                                           192        24       (105)       (6)            105
ESPP                                                            79        20          -       (14)             85
1990 US(1)                                                     167         -        (46)        -             121
1995 US(2)                                                     190         -        (35)        -             155
_________________________________________________________________________________________________________________
Total                                                        4,876       978     (1,581)     (401)          3,872
_________________________________________________________________________________________________________________

NOTES
 1 The OraVax 1990 Stock Incentive Plan
 2 The OraVax 1995 Stock Incentive Plan

The  following  table shows  outstanding  options,  divided  into ranges to help
assess the number and  timing of  additional  shares  that may be issued and the
cash that may be received upon exercise of those options.

                                                       Weighted average  Period exercisable in           Number
Year of grant                                            exercise price   normal circumstances      outstanding
_________________________________________________________________________________________________________________

1996                                                               $26.02              1999-2006           30,547
1996                                                              GBP1.70              1999-2006           17,685
1997                                                                $4.89              2000-2007          105,443
1999                                                                $1.68              2002-2009            5,090
1999                                                              GBP0.36              2002-2009           85,434
2000                                                              GBP0.92              2003-2006          250,000
2000                                                              GBP0.96              2003-2010            3,600
2001                                                              GBP1.25              2004-2006          208,000
2001                                                              GBP3.33              2004-2006           19,520
2001                                                              GBP1.38              2004-2011          258,201
2002                                                              GBP2.46              2005-2006          237,152
2002                                                              GBP1.80              2005-2006           16,065
2002                                                              GBP2.62              2005-2012          363,419
2003                                                              GBP3.26              2006-2007          265,716
2003                                                              GBP2.74              2006-2007            8,346
2003                                                              GBP3.00              2006-2013          359,265
2004                                                              GBP2.65                   2006           24,798
2004                                                              GBP2.81              2007-2008          377,340
2004                                                              GBP2.36              2007-2008           17,896
2004                                                              GBP2.91              2007-2014          462,949


                                                       Weighted average  Period exercisable in           Number
Year of grant                                            exercise price   normal circumstances      outstanding
_________________________________________________________________________________________________________________

2005                                                              GBP1.87                   2007           50,652
2005                                                              GBP2.46              2008-2009          344,440
2005                                                              GBP2.01              2008-2009           38,414
2005                                                              GBP2.34              2008-2015          479,895
_________________________________________________________________________________________________________________
Total                                                                                                   4,029,867
_________________________________________________________________________________________________________________

The  weighted  average  share  price of the  1,419,620  options  exercisable  at
December 31, 2005 was GBP2.70.

Whilst they have no present intention of utilizing such authority, at the AGM to
be held on 23 June 2006 the Directors will seek authority from the  shareholders
to allot shares up to an aggregate  nominal  value of  GBP3,264,670  (32,646,703
ordinary shares of 10p each), being the un-issued ordinary shares of Acambis plc
at 21 April 2006. Currently,  the Directors have authority to allot shares up to
an aggregate nominal value of GBP3,276,481.

The Group operates an HM Revenue and Customs-approved  SAYE scheme in the UK and
an ESPP scheme in the US.

CHARGE IN THE INCOME STATEMENT
In accordance with the transitional  provisions of IFRS2, Acambis has recognized
an expense in respect of all grants under these plans made after 7 November 2002
which remained unvested at December 31, 2004. Acambis recognized a total expense
of GBP0.8m in 2005 (2004 - GBP0.7m) in accordance with IFRS2.

FINANCIAL DETAILS OF SHARE OPTIONS
Options were  exercised on a regular  basis during the year.  The average  share
price during 2005 was GBP2.35.  The weighted average fair values for grants made
in the year are as  noted in the  table  below.  Grants  made to  employees  and
Directors  under the 1996 and 1999 Plans are shown  separately  since  different
inputs have been used for these grants.


                                                                   2005    2004
Weighted  average fair value
                                                                    GBP     GBP
________________________________________________________________________________
1996 Plan (Employee  grants)                                         0.83   1.12
1996 Plan (Director grants)                                           N/A   1.36
1999 Plan (Employee grants)                                          0.68   1.03
1999 Plan (Director grants)                                          0.84   1.19
LTIP                                                                 1.41   2.37
ESPP                                                                 0.62   1.36
SAYE                                                                 0.88   1.16
________________________________________________________________________________

The assumptions used in the calculation of the fair values in the above table
are:

*  Expected volatility was based on the historical volatility of the Acambis plc
   share price:
   -   over the three years prior to the grant date for employee grants under
       the 1996 and 1999 Plan and all grants under the SAYE Scheme and LTIP;
       - over the four years prior to the grant date for Director grants under
       the 1996 and 1999 Plan; and
   -   over the two years prior to the grant date for all grants under the ESPP.
 *   A zero dividend yield assumption has been used in the calculation of these
     fair values.
1996 PLAN, 1999 PLAN AND LTIP
The fair value of shares awarded under the 1996 Plan and 1999 Plan is calculated
using a binomial option pricing model adjusted to reflect the TSR market-based
performance condition. The awards were calculated using the following
assumptions:

1996 PLAN (EMPLOYEE GRANTS)
                                                               2005         2004
________________________________________________________________________________

Weighted average share price (GBP)                             2.58         3.00
Weighted average exercise price (GBP)                          2.58         2.93
Weighted average volatility (%)                                41.4         51.1
Weighted average correlation (%)                                5.0         14.8
Weighted average expected life (years)                          3.5          3.5
Weighted average risk-free interest rate (%)                    4.6          4.7
________________________________________________________________________________

1996 PLAN (DIRECTOR GRANTS)
                                                              2005         2004
________________________________________________________________________________
Weighted average share price (GBP)                             N/A         3.46
Weighted average exercise price (GBP)                          N/A         3.46
Weighted average volatility (%)                                N/A         53.6
Weighted average correlation (%)                               N/A         14.3
Weighted average expected life (years)                         N/A         4.00
________________________________________________________________________________
Weighted average risk-free interest rate (%)                   N/A          4.6
________________________________________________________________________________

1999 PLAN (EMPLOYEE GRANTS)
                                                               2005         2004
________________________________________________________________________________
Weighted average share price (GBP)                            2.41         2.85
Weighted average exercise price (GBP)                         2.41         2.84
Weighted average volatility (%)                               36.9         50.2
Weighted average correlation (%)                               4.3         14.9
Weighted average expected life (years)                         3.1          3.5
Weighted average risk-free interest rate (%)                   4.3          4.7
________________________________________________________________________________
1999 PLAN (DIRECTOR GRANTS)
                                                              2005         2004
________________________________________________________________________________
Weighted average share price (GBP)                            2.34         3.05
Weighted average exercise price (GBP)                         2.34         3.04
Weighted average volatility (%)                               47.9         52.0
Weighted average correlation (%)                               4.5         14.5
Weighted average expected life (years)                         4.0          3.7
Weighted average risk-free interest rate (%)                   4.3          4.7
________________________________________________________________________________

LTIP
                                                              2005         2004
________________________________________________________________________________
Weighted average share price (GBP)                            2.19         3.46
Weighted average exercise price (GBP)                            -            -
Weighted average volatility (%)                               40.8         53.3
Weighted average correlation (%)                               5.0         15.0
Weighted average expected life (years)                         3.0          3.0
Weighted average risk-free interest rate (%)                   4.3          4.5
________________________________________________________________________________

The  1996  Plan,  1999  Plan and the LTIP  have a TSR  market-based  performance
condition,  such that the  Acambis plc TSR over the  performance  period will be
compared  with the TSR of the  comparator  companies  on the date of grant.  The
maximum number of shares would vest if Acambis were ranked in the upper quartile
of the  comparator  group,  being prorated down to a 30% vesting at a ranking of
the median. No shares vest if Acambis' ranking falls below the median.  The fair
value of options  under the 1996 Plan,  1999 Plan and LTIP has been  adjusted to
take into account this market-based  performance condition using a pricing model
based on  expectations  about  volatility  and the  correlation  of share  price
returns in the group of  comparator  companies and which  incorporates  into the
valuation the interdependency between share price performance and TSR vesting.


ESPP AND SAYE GRANTS
The fair value of options  granted under the ESPP and SAYE scheme are calculated
using a binomial option pricing model with the following assumptions:

ESPP
                                                               2005        2004
________________________________________________________________________________
Weighted average share price (GBP)                              2.17        3.44
Weighted average exercise price (GBP)                           1.87        2.65
Weighted average volatility (%)                                 32.4        44.8
Expected life (years)                                            2.0         2.0
Weighted average risk-free interest rate (%)                     4.4         5.0
________________________________________________________________________________
                                                                2005        2004
________________________________________________________________________________
   Weighted average share price (GBP)                           2.39        3.51
   Weighted average exercise price (GBP)                        2.01        2.74
   Weighted average volatility (%)                              34.7        55.2
   Expected life (years)                                         3.3         3.3
   Risk-free interest rate (%)                                   4.3         4.9
________________________________________________________________________________

FAIR VALUE OF OPTIONS GRANTED IN 2003
The charge  under  IFRS2 for the  current  period  includes a charge for options
granted under the above schemes  during the year ended December 31, 2003 and the
year ended December 31, 2002 with the following weighted average grant date fair
values:

                                                               2003         2002
                                                               GBP           GBP
________________________________________________________________________________
   1996 Plan (Employee grants)                                 1.25         1.11
   1996 Plan (Director grants)                                  N/A          N/A
   1999 Plan (Employee grants)                                  1.23        1.13
   1999 Plan (Director grants)                                  1.33         N/A
   LTIP                                                         2.24         N/A
   ESPP                                                         1.66         N/A
   SAYE                                                         1.78         N/A
________________________________________________________________________________

The fair values for the 2003 grants were  calculated  using the  binomial  model
(adjusted for the TSR performance condition where relevant).

                                          1996 Plan   1996 Plan    1999 Plan  1999 Plan
                                          (Employee   (Director    (Employee  (Director
                                            grants)     grants)      grants)    grants)  LTIP   ESPP  SAYE
                                      ____________________________________________________________________

Weighted average share price (GBP)            3.34         N/A         3.21       2.94   3.23  3.72   3.51
Weighted average exercise price (GBP)         3.34         N/A         3.17       2.94      -  3.08   2.74
Weighted average volatility (%)               55.0         N/A         55.8       63.7   55.2  59.2   55.2
Weighted average expected life                 3.2         N/A          3.3        4.0    3.0   2.0    3.3
(years)
Weighted average risk-free
interest rate (%)                              4.5         N/A          4.4        4.4    3.8   3.4    4.9
__________________________________________________________________________________________________________

The fair values for the 2002 grants were  calculated  using the  binomial  model
(adjusted for the TSR performance condition where relevant).



                                          1996 Plan   1996 Plan    1999 Plan  1999 Plan
                                          (Employee   (Director    (Employee  (Director
                                            grants)     grants)      grants)    grants)   LTIP  ESPP   SAYE
                                      _______________________________________________________________________

Weighted average share price (GBP)            2.47         N/A         2.52        N/A    N/A   N/A    N/A
Weighted average exercise price (GBP)         2.47         N/A         2.52        N/A    N/A   N/A    N/A
Weighted average volatility (%)               66.8         N/A         66.7        N/A    N/A   N/A    N/A
Weighted average expected life (years)         3.5         N/A          3.5        N/A    N/A   N/A    N/A
Weighted average risk-free
interest rate (%)                              4.3         N/A          4.4        N/A    N/A   N/A    N/A
__________________________________________________________________________________________________________

For the  options  granted  under the 1996 Plan and 1999 Plan prior to January 1,
2004 where the TSR  condition is retested at the end of year four (if not met at
the end of year three)  and/or at the end of year five (if not met at the end of
year  four),  a three  years  and six  months  vesting  period  has been used to
approximate  the  impact of the  retesting  condition  on the fair  value.  This
retesting  condition  applies to a limited  number of option grants and does not
apply to new option grants.

25       FINANCIAL COMMITMENTS

i) LEASE COMMITMENTS
The minimum lease payments under operating leases are as follows:

                                                                             Land and
                                                                            buildings  Plant and machinery
                                                                    ______________________________________
                                                                        2005     2004      2005       2004
                                                                        GBPm     GBPm      GBPm       GBPm
__________________________________________________________________________________________________________
Total commitments under operating lease:
Due within one year                                                      2.3      1.7       0.1        0.1
Due within one to five years                                             9.6      3.1       0.2        0.1
Due beyond five years                                                    8.2      7.7         -          -
__________________________________________________________________________________________________________
                                                                        20.1     12.5       0.3        0.2
__________________________________________________________________________________________________________


In March 2000,  the Group entered into a sub-lease  with Medivir UK Limited with
respect to a part of the facility at  Peterhouse  Technology  Park in the UK. In
December  2003,  this  sub-lease was amended,  such that 45% of the facility was
rented to Medivir until November 2004. During 2004, Medivir  contributed GBP0.2m
in operating lease rentals relating to land and buildings (2005 - GBPnil).

ii) CAPITAL COMMITMENTS

At the end of the year, capital commitments contracted but not provided for were
GBP0.1m (2004 - GBP0.2m).


iii) PENSION ARRANGEMENTS
The Group  provides  pension  benefits to all  full-time  employees on a defined
contribution basis.  Employees may operate private personal pension schemes. The
normal age of retirement for UK staff is 65 years. In the US, the Group offers a
'401k  Savings  and  Retirement  Plan' for all  employees,  including  Executive
Directors.  The Group  pension  cost  (including  401k  costs)  for the year was
GBP0.4m  (2004 -  GBP0.4m).  At the  year-end,  the Group owed  GBP0.2m  (2004 -
GBP0.2m) to the pension schemes. This amount is shown in the balance sheet under
'accruals and deferred income'.

26       RELATED PARTY TRANSACTIONS

For the year ended December 31, 2005, the Group has included  turnover of GBPnil
(2004 - GBP0.1m) in respect of costs  incurred in  performing  services  for the
Joint Venture and a loss of GBPnil (2004 - GBP0.1m)  within its Group  financial
statements.  At  December  31,  2005,  the  amounts  the Group owed to the Joint
Venture amounted to GBP0.4m (2004 - GBP0.3m).

Amounts owed by the Joint Venture to the Group at December 31, 2005 were GBP0.3m
(2004 - GBP0.3m).

DIRECTORS' REMUNERATION, INTERESTS AND TRANSACTIONS
Full disclosure of Directors' remuneration,  interests and transactions is given
in  that  part  of the  remuneration  report  that is  required  to be  audited.
Aggregate  gains made by Directors on the exercise of share options were GBP0.1m
(2004 - GBP1.8m).



KEY MANAGEMENT COMPENSATION
The remuneration received by key management personnel,  including the Directors,
is as follows:

                                                                      
                                                                  2005      2004
                                                                  GBPm      GBPm
________________________________________________________________________________
Salaries and short-term employee benefits                          1.6       1.5
Post-employment benefits                                           0.1       0.1
Other long-term benefits                                             -         -
Termination benefits                                                 -       0.2
Share-based payments                                               0.3       0.2
________________________________________________________________________________
                                                                   2.0       2.0
________________________________________________________________________________


Key management  personnel are those persons having authority and  responsibility
for planning, directing and controlling the activities of the Group, directly or
indirectly,  including all Executive and Non-executive  Directors. The number of
key management personnel whose remuneration is included above is 11 (2004 - 12).

DIRECTORS' INTERESTS

No Director or key  management  personnel  had any  disclosable  related  party
transactions with the Group during the year.

27       RECONCILIATION OF EQUITY AND PROFIT UNDER UK GAAP TO IFRS

With effect from January 1, 2005,  Acambis has prepared  consolidated  financial
statements under IFRS. The comparative  information for the year to December 31,
2004 that was previously  reported under UK GAAP has been restated in accordance
with IFRS.  In order to understand  the impact of transition to IFRS,  this note
provides  reconciliations of certain information  previously  presented under UK
GAAP to the amounts restated in accordance with IFRS.


EXPLANATORY NOTES
The notes  below  explain  the impact  that the  adoption of IFRS has had on the
Group's consolidated results.

i) IFRS1 'FIRST TIME ADOPTION OF IFRS'
The Group has taken advantage of the following exemptions available under IFRS1:

*   To apply IFRS3 'Business combinations' from August 2003;
*   To treat all at cumulative translation differences on overseas subsidiaries
    as zero at the date of transition to IFRS; and
*   Not to apply IFRS2 'Share based payments' to awards made before 7 November
    2002, and that had not vested at December 31, 2004.

ii) IFRS3 'BUSINESS COMBINATIONS'
Under UK GAAP,  the  excess of  consideration  over the fair value of net assets
acquired was  recognized  as goodwill,  and amortized  over its useful  economic
life.  Under IFRS,  intangible  assets  acquired in a business  combination  are
recognized  at  their  fair  value  subject  to  meeting  the  definition  of an
intangible asset as set out in IAS38 'Intangible  assets'. The residual goodwill
is not subject to amortization, and is tested annually for impairment along with
any other  indefinite  life  assets in  accordance  with  IAS36  'Impairment  of
assets'.  Intangible  assets  acquired in a business  combination are tested for
impairment when there are indicators that the asset is impaired.

The adoption of IFRS3 has had the following impact:
 *   Amortization of goodwill for Acambis Inc. ceases from January 2004;
 *   Amortization of goodwill for BPC ceases from August 2003; and
 *   The application of IFRS to the BPC acquisition in 2003 has resulted in the
     creation of an intangible asset and associated deferred tax liability and a
     reduction in the carrying amount of goodwill.

iii) IFRS2 'SHARE-BASED PAYMENTS'
Acambis  offers share  options to employees as an employment  benefit.  Under UK
GAAP,  no accounting  charge is made for share  options  issued at market value.
Under IFRS, a fair value must be  calculated  and  recognized as an expense over
the vesting  period,  with a corresponding  increase in equity.  Deferred tax is
recognized on share options where there is a temporary timing difference,  which
arises  when the  accounting  book value and the tax book  value of the  options
differ.

The charge  previously  made relating to UITF 17 (Revised 2003)  'Employee Share
Schemes' has been reversed, as it is replaced by the IFRS2 charge.  Deferred tax
is  calculated  based on the expected  tax  deduction on exercise of the options
compared  to the  accounting  charge  on grant of the  option.  Acambis  has not
provided  for any  increase  in a deferred  tax asset.  Under  IFRS,  income tax
relating to items recognized  directly in equity is recognized in equity and not
in the income statement, resulting in a movement between the tax charge under UK
GAAP and equity under IFRS.

iv) IAS38 'INTANGIBLE ASSETS'
IAS38 has had the following impact:
*   Capitalized software has been reclassified from 'property plant and
    equipment' to 'intangible assets'; and
*   Certain intangible assets acquired in a business are recognized at their
    value as described in explanatory note (ii).

IAS38  also  requires   capitalization  of  development  costs  incurred  on  an
individual project if, and only if, specific criteria are met.  Previously under
UK GAAP,  this was an  alternative  treatment.  Management  has  reviewed  these
criteria  and  it is  our  opinion  that  it is  not  possible  to  satisfy  the
requirement to demonstrate the technical  feasibility of a project,  and that it
will generate  probable future  economic  benefits,  until final  submission for
regulatory approval has been obtained.  Therefore, the Group has not capitalized
any internally generated development costs to date.

v) IAS12 'INCOME TAX'
Under IFRS deferred tax is recognized on taxable temporary  differences  arising
between the tax base and the accounting  base of balance sheet items.  The scope
of IAS12 is wider  than the  corresponding  UK GAAP  standards,  and means  that
deferred tax is recognized on certain temporary  differences that would not have
given rise to deferred tax under UK GAAP. For Acambis,  the main  differences on
adoption of IFRS arise in relation to intangible  assets  acquired in a business
combination and share-based payments.

vi) IAS17 'LEASES'
Under IAS17,  the presentation of the Canton finance lease facility differs from
that under UK GAAP. Under IFRS the asset is restated to the net present value of
the minimum  lease  payments,  with a  corresponding  entry  recorded as a lease
creditor. This is unwound over the period of the lease.

vii) IAS21 'THE EFFECTS OF CHANGES IN FOREIGN EXCHANGE RATES'
Cumulative  exchange  differences  arising on the  retranslation  of the Group's
overseas subsidiaries are reported as a separate component of equity under IFRS.
There is no impact on the balance at transition  as Acambis has taken  advantage
of the exemption available under IFRS1, as described above.

viii) IAS7 'CASH FLOW STATEMENT'

The  following  differences  have  arisen  between  the  consolidated  cash flow
statement presented under UK GAAP, and the consolidated  statement of cash flows
prepared under IFRS:

 * Reclassification of certain liquid investments as cash and cash equivalents;
     and
 * Reduction in the amounts disclosed as 'purchases of liquid investments' and
   'sale of liquid investments'. The adoption of IFRS had no material impact on
   the underlying cash flows of the Group.

ix) IAS39 'RECOGNITION AND MEASUREMENT OF FINANCIAL INSTRUMENTS'
Under IFRS,  derivative financial  instruments are recorded at fair value, which
has resulted in a net decrease in assets of GBP0.1m at January 1, 2005.



RECONCILIATION OF PROFIT FOR YEAR ENDED DECEMBER 31, 2004

________________________________________________________________________________________________________
                                                                                         
                                                                           UK GAAP    Adjustment     IFRS
                                                              Note            GBPm         GBPm     GBPm
________________________________________________________________________________________________________
Revenue                                                       (ii)            85.5            -     85.5
Cost of sales                                                                (34.3)        (0.7)   (35.0)
________________________________________________________________________________________________________
Gross profit                                                                  51.2         (0.7)    50.5
Research and development costs                               (iii)           (28.9)        (0.4)   (29.3)
Sales and marketing costs                                    (iii)            (2.7)        (0.1)    (2.8)
Administration costs including costs relating to Canton     (i),
plant impairment and restructuring costs                    (ii),
                                                             (iii)            (7.7)         2.2     (5.5)
Other operating income - settlement of Canton agreement                       10.2            -     10.2
________________________________________________________________________________________________________
Operating profit                                                              22.1          1.0     23.1
Non-operating income                                                           0.2         (0.2)       -
Finance income                                                                 4.8            -      4.8
Finance costs                                                                 (0.9)           -     (0.9)
________________________________________________________________________________________________________
Profit before tax                                                             26.2          0.8     27.0
Taxation                                                       (v)            (6.4)        (0.9)    (7.3)
________________________________________________________________________________________________________
Profit for the year attributable to shareholders                              19.8         (0.1)    19.7
________________________________________________________________________________________________________
Earnings per ordinary share (basic)                                           18.6p        (0.1)p   18.5p
Earnings per ordinary share (fully diluted)                                   18.2p        (0.1)p   18.1p



 RECONCILIATION OF EQUITY DECEMBER 31, 2004

________________________________________________________________________________________________________
                                                                           UK GAAP   Adjustment     IFRS
                                                               Note           GBPm         GBPm     GBPm
________________________________________________________________________________________________________
Assets
Non-current assets
Goodwill                                                       (ii)           16.0         (0.6)    15.4
Other intangible assets                                       (ii),              -          4.1      4.1
                                                               (iv)
Property, plant and equipment                                 (iv),           17.5          1.0     18.5
                                                               (vi)
Other non-current assets                                                       2.5            -      2.5
________________________________________________________________________________________________________
                                                                              36.0          4.5     40.5
Current assets
Inventory                                                                      6.0            -      6.0
Trade and other receivables                                                   13.7            -     13.7
Current tax assets                                                             1.9            -      1.9
Liquid investments                                           (viii)           70.9        (50.1)    20.8
Cash and cash equivalents                                    (viii)           30.9         50.1     81.0
________________________________________________________________________________________________________
                                                                             123.4            -    123.4
Liabilities
Current liabilities
Interest-bearing loans and borrowings                                         (6.7)           -     (6.7)
Trade and other payables                                                      (8.3)           -     (8.3)
Accruals and deferred income                                   (vi)          (26.6)        (1.3)   (27.9)
Derivative financial instruments                               (ix)              -         (0.1)    (0.1)
Income tax payable                                                            (4.6)           -     (4.6)
                                                                             (46.2)        (1.4)   (47.6)
________________________________________________________________________________________________________
Net current assets                                                            77.2         (1.4)    75.8
Non-current liabilities
Investment in Joint Venture                                                   (0.3)           -     (0.3)
Long-term financial liabilities                                               (6.3)           -     (6.3)
Other non-current liabilities                                                 (0.5)           -     (0.5)
Deferred income tax liabilities                                (ii)           (0.1)        (1.6)    (1.7)
                                                                              (7.2)        (1.6)    (8.8)
________________________________________________________________________________________________________
Net assets                                                                   106.0          1.5    107.5
________________________________________________________________________________________________________
Shareholders' equity
Share capital                                                                 10.7            -     10.7
Share premium                                                                 97.8            -     97.8
Other reserves                                                (vii)              -         (2.5)    (2.5)
Retained earnings                                                             (2.5)         4.0      1.5
________________________________________________________________________________________________________
Total shareholders' equity                                                   106.0          1.5    107.5
________________________________________________________________________________________________________


RECONCILIATION OF EQUITY AT 1 JANUARY 2004

________________________________________________________________________________________________________
                                                                           UK GAAP   Adjustment     IFRS
                                                               Note           GBPm         GBPm     GBPm
________________________________________________________________________________________________________
Assets
Non-current assets
Goodwill                                                       (ii)           18.4         (2.9)    15.5
Other intangible assets                                       (ii),            0.8          4.9      5.7
                                                               (iv)
Property, plant and equipment                                 (iv),           21.0          2.6     23.6
                                                               (vi)
Deferred tax assets                                                            2.1            -      2.1
Other non-current assets                                                       0.1            -      0.1
________________________________________________________________________________________________________
                                                                              42.4          4.6     47.0
Current assets
Inventory                                                                     18.2            -     18.2
Trade and other receivables                                                   10.2            -     10.2
Liquid investments                                           (viii)           62.0        (44.2)    17.8
Cash and cash equivalents                                    (viii)           63.2         44.2    107.4
________________________________________________________________________________________________________
                                                                             153.6            -    153.6
Liabilities
Current liabilities
Trade and other payables                                                     (15.4)           -    (15.4)
Interest-bearing loans and borrowings                                         (6.9)           -     (6.9)
Accruals and deferred income                                   (vi)          (74.3)        (1.4)   (75.7)
Income tax payable                                                            (0.3)           -     (0.3)
                                                                             (96.9)        (1.4)   (98.3)
________________________________________________________________________________________________________
Net current assets                                                            56.7         (1.4)    55.3
Non-current liabilities
Investment in Joint Venture                                                   (0.3)           -     (0.3)
Long-term financial liabilities                                               (9.6)           -     (9.6)
Accruals and deferred income                                   (vi)           (0.1)        (1.4)    (1.5)
Other non-current liabilities                                                 (2.6)           -     (2.6)
Deferred income tax liabilities                                (ii)              -         (1.8)    (1.8)
                                                                             (12.6)        (3.2)   (15.8)
________________________________________________________________________________________________________
Net assets                                                                    86.5            -     86.5
________________________________________________________________________________________________________
Shareholders' equity
Share capital                                                                 10.6            -     10.6
Share premium                                                                 96.0            -     96.0
Retained earnings                                                            (20.1)           -    (20.1)
Total shareholders' equity                                                    86.5            -     86.5
________________________________________________________________________________________________________




28    RECONCILIATION TO US ACCOUNTING PRINCIPLES
SUMMARY OF SIGNIFICANT DIFFERENCES BETWEEN IFRS FOLLOWED BY THE GROUP AND US
GAAP

The Group's financial statements have been prepared under IFRS, which differs in
certain significant respects from US GAAP. The principal differences between the
Group's  accounting  policies under IFRS and US GAAP are set out below. As noted
in Note 1 of the financial statements,  the consolidated financial statements of
Acambis have been prepared, for the first time, in accordance with IFRS.

a) MULTIPLE-ELEMENT ARRANGEMENTS
The $428m ACAM2000  contract  awarded in November 2001 consists of two principal
components:  to manufacture 155 million doses of smallpox  vaccine;  and to take
the vaccine through clinical trials to FDA licensure.

Under  IFRS,   this  contract  has  been  accounted  for  as  a   single-element
arrangement.  As detailed in note 1 of the  financial  statements,  turnover and
profits  are  recognized  according  to the  extent  of  performance  under  the
contract, based on the proportion of costs incurred to date divided by the total
estimated costs to complete.  All research and development costs are expensed as
incurred  and  manufacturing  costs are held on the balance  sheet as  inventory
until relevant criteria for revenue recognition are met.

Under US GAAP, the Group treats this contract as a multiple-element arrangement,
resulting in a different  allocation of revenue  compared to the IFRS treatment.
The two primary elements of the contract (the  manufacturing and the development
portions)  each are  separable  deliverables  which  have  value to the CDC on a
standalone  basis  and have  fair  values  which are  objectively  and  reliably
determinable.  In addition,  each of the deliverables is accounted for under SAB
104, not under a percentage to complete model.

For  purposes  of US GAAP,  the  Group  has  determined  the  fair  value of the
development  and  manufacturing  portions of the contract and has  allocated the
total contract value to the  development  and  manufacturing  using the relative
fair value method as prescribed  by Emerging  Issues Task Force (EITF) Issue No.
00-21, 'Accounting for Revenue Arrangements with Multiple Deliverables'.
The development portion of the contract consists of the completion of Phase I/II
clinical  trials,  completion  of Phase  III  clinical  trials,  completion  and
submission of a Biologics License Application with the FDA and post FDA approval
activities.  The manufacturing  portion consists of the manufacture and delivery
of smallpox vaccine to the CDC.
The fair values were determined using the US regulations and guidance applicable
to government  contracts  utilizing  specifically  the  contracting  regulations
stipulated  in the  Federal  Acquisition  Regulation  (FAR),  together  with the
evidence provided by the Group's ACAM1000  contract.  After determining the fair
value of the two elements of the contract,  as noted above,  the Group allocated
the  arrangement  consideration  to the separate  units of accounting  using the
relative fair value method.  $152m of the ACAM2000 contract was allocated to the
research  and  development  element  and $276m  allocated  to the  manufacturing
element.

The table  below  shows total  revenue  recognized  relating to each major class
under the $428m contract in 2005 and 2004:



                                                                        
                                                               Year ended Dec 31
                                                               2005         2004
                                                              GBPm          GBPm
________________________________________________________________________________
Development                                                    20.3         21.6
Manufacturing                                                     -         33.7
________________________________________________________________________________
Total revenue under US GAAP for the contract                   20.3         55.3
________________________________________________________________________________





Under US GAAP, with respect to the development work, revenue is recognized under
the proportional performance method as services are provided under the contract.
The  development  work has been further broken down into three  distinct  phases
consisting of:
o        four phase I/II clinical trials;
o        two phase III clinical trials; and
o        submitting IND and obtaining FDA approval.
The  development  revenue was allocated to these three distinct phases using the
relative fair value method using the same  methodology  to determine  fair value
that was  applied to the  development  services as a whole as noted  above.  The
Group  determined  this  was  necessary  because  the  level of  effort  was not
consistent  throughout  each of these phases.  Therefore,  after  allocating the
revenue to each of these phases,  such revenue was recognized on a straight-line
basis over the  expected  performance  period of each  phase.  Relevant  cost of
revenue is  recorded  on an accrual  basis as actual  costs are  incurred;  this
contrasts  with the IFRS  treatment,  where revenues are recognized as costs are
incurred, using the principles of long-term contract accounting.

Manufacturing  costs were held on the  balance  sheet as  'inventory'  until the
relevant criteria for revenue  recognition are met. The Group recognized revenue
on the  manufacturing  portion of the contract as smallpox vaccine was delivered
to the CDC. Thus,  manufacturing revenue and costs were recognized in the income
statement  on the  transfer  of the risks and  rewards of  ownership,  typically
through  delivery  of product to the  customer's  premises,  assuming  all other
revenue recognition criteria were met at this time.
Costs  associated with expected  re-labeling to be undertaken in the future were
being accrued as smallpox  vaccine was  delivered to the CDC.  Costs and revenue
associated with providing storage or vaccine disposal services are only included
when, and if, it is deemed probable that such services will be performed.

b) INVENTORY SUBJECT TO DEFERRED REVENUE ARRANGEMENTS
In the case of inventory subject to deferred revenue arrangements,  the criteria
specified  for  determining  whether  the risks and  rewards of  ownership  have
transferred  differ between IFRS and US GAAP. At December 31, 2004, a proportion
of revenue  relating to certain batches of smallpox  vaccine were required to be
recognized under IFRS the relevant recognition criteria having been met. US GAAP
stipulates  additional  criteria,  including  that all components of the vaccine
have been  delivered.  As at December 31, 2004 certain batches did not meet this
criterion,  with the result that the costs and revenues were not recognizable in
the year  ended  December  31,  2004  under US  GAAP.  Accordingly,  the cost of
inventory  of GBP0.3m  which was expensed  under IFRS  remained  capitalized  as
inventory under US GAAP at December 31, 2004, and related revenue of GBP0.5m was
not recognized under US GAAP at December 31, 2004.

During 2005 the batches met the additional  criteria,  in that all components of
the vaccine were delivered. Therefore the GBP0.3m was expensed from inventory to
cost of revenue and the related revenue of GBP0.5m was recognized.

c) LICENSE FEES
Under IFRS certain license fees were  recognized when paid,  where such payments
were  not  refundable.   Under  US  GAAP  the  Group  follows  SAB104,  'Revenue
Recognition  in  Financial  Statements',  and where  such  license  fees are not
refundable and are not credited  against  associated R&D activities,  these fees
are  considered  inseparable  from the  associated  R&D effort.  As such,  those
license fees are deferred and recognized  over the period of the license term or
over the period of the R&D  agreement.  Deferred  revenues  relating to research
programs terminated during this period are released to revenue on termination of
the program.





                                                                         
                                                               Year ended Dec 31
                                                                 2005       2004
                                                                 GBPm       GBPm
________________________________________________________________________________
Revenue recognized under IFRS                                    40.9       85.5
Multiple-element arrangements                                     7.5       17.5
Deferred revenue arrangements                                     0.5      (0.5)
License fees                                                      0.9          -
________________________________________________________________________________
Revenue recognized under US GAAP                                 49.8      102.5
________________________________________________________________________________



d) TAX
i) EFFECTS OF REVENUE ADJUSTMENTS
As the  majority  of the profit in relation  to the  development  portion of the
$428m  ACAM2000  contract is recorded in the Group's UK  operations,  any timing
difference on the recognition of profit gives rise to a temporary  difference at
the UK tax rate of 30%.

As the profit in relation  to the  manufacturing  portion of the $428m  ACAM2000
contract  and  any  profit  that  is   associated   with   'deferred   inventory
arrangements'  and license  fees are recorded in the US  operations,  any timing
difference on the recognition of profit gives rise to a temporary  difference at
the marginal US tax rate of 41%. These temporary differences are included within
'net tax effect of US GAAP adjustments' in the reconciliations of net profit and
shareholders' equity. A valuation allowance may be recorded against deferred tax
assets  arising  from  operating  loss carry  forwards  in  accordance  with the
criteria described under 'Deferred Tax' below.

ii) TAX ON EMPLOYEE SHARE OPTIONS
The Group is entitled to a tax deduction for the amount treated as  compensation
under US and UK tax rules for certain employee share options.

The deduction arises on exercise of the option,  while any compensation  expense
is recorded over the vesting period of the option.

Under US GAAP, the tax benefit arising on Incentive Stock Options in the US (and
on options with similar  characteristics granted outside the US) is recorded, in
equity,  in the  period in which the  option is  exercised  and the tax  benefit
arises.  In respect  of  non-qualifying  options in the US (and on options  with
similar  characteristics  granted  outside  the  US)  deferred  tax  assets  are
calculated by multiplying the compensation  expense recorded in respect of these
options by the prevailing tax rate in the relevant tax  jurisdiction.  Valuation
allowances are recorded  against such deferred tax assets unless  utilization of
the assets against  future taxable  profits is more likely than not, as assessed
in accordance  with the criteria in SFAS 109. Where, on exercise of the relevant
option,  the tax benefit  obtained exceeds the deferred tax asset in relation to
the relevant  options,  the excess is recorded in  additional  paid-in  capital.
Where the tax benefit is less than the deferred tax asset, the write-down of the
deferred tax asset is recorded against  additional paid-in capital to the extent
of previous  excesstaxbenefits  recorded  in this  account,  with any  remainder
recorded in the income statement.

Under  IFRS the  deferred  tax asset  arising is  calculated  by  comparing  the
estimated amount of tax deduction to be obtained in the future (based on Acambis
plc  share  price at the  balance  sheet  date)  with the  cumulative  amount of
compensation  expense  recorded  in  the  income  statement.  If the  amount  of
estimated future tax deduction exceeds the cumulative amount of the remuneration
expense at the  statutory  rate,  the  excess is  recorded  directly  in equity,
against the profit and loss reserve.  Deferred tax assets are recognised only if
the utilisation of the assets against future taxable profits is more likely than
not.

e) COMPENSATION  COSTS UNDER VARIABLE PLAN ACCOUNTING FOR SHARE OPTIONS AND SAYE
PLAN DISCOUNT Acambis has granted share options to employees that will vest upon
the attainment of certain targets.


Under IFRS,  the cost of these  equity-settled  transactions  with  employees is
measured by reference to the fair value at the date of grant.  The fair value is
determined  using a binomial option pricing model, as described in note 1 of the
financial  statements.  Under US GAAP, APB Opinion No. 25, 'Accounting for Stock
Issued to  Employees'  (APB25),  the Group is required to follow  variable  plan
accounting for these grants and measure  compensation  expense as the difference
between the exercise  price and the fair market value of the related share under
option  during each  accounting  period over the vesting  period of the options.
Increases in fair market value of the share result in a charge to operations and
decreases  in the  fair  market  value  of  the  share  result  in a  credit  to
operations, limited to the cumulative amount previously expensed. Under US GAAP,
in  accounting  for new offers made under the SAYE plan since  January 24, 2002,
Acambis follows the requirements of pronouncement EITF 00-23 'Issues relating to
the  Accounting  for  Stock  Compensation  under  APB25  and  FIN44'  (Financial
Accounting  Standards  Board  Interpretation  Number (FIN) 44,  'Accounting  for
Certain Transactions  Involving Stock Compensation',  (FIN44)). The compensation
charge under US GAAP in respect of such plans is calculated using one of the two
following methods:

1)   Under normal  circumstances,  where the plan qualifies as a fixed plan, the
     compensation  charge is the  difference  between  the  market  price of the
     shares at the date of grant and the  exercise  price of the  option  and is
     recorded on a straight-line basis over the vesting period.

2)   Where a SAYE  scheme is  offered at a lower  price than a previous  scheme,
     variable  accounting  commences for all existing  higher priced awards when
     the offer is made.  For those  awards that are  retained  by the  employees
     because  the  new  lower-priced  offer  is  declined,  variable  accounting
     continues  until  the  awards  are  exercised,  are  forfeited,  or  expire
     unexercised.  New awards are  accounted  for as variable to the extent that
     previous higher priced options are cancelled.

The table shows the (credit)/charge made to the group income statement under US
GAAP.



                                                                         
                                                               Year ended Dec 31
                                                                 2005       2004
                                                                 GBPm       GBPm
________________________________________________________________________________
(Credited)/charged to the Group income statement                (0.4)        0.6
________________________________________________________________________________



f) PURCHASE PRICE ACCOUNTING, GOODWILL AND INTANGIBLES
Under both IFRS and US GAAP,  goodwill  is the amount by which the fair value of
the  purchase  consideration  exceeds  the fair  value of  assets  acquired.  As
explained in note 27 of the financial  statements,  on adoption of IFRS in 2005,
the  Group  took  advantage  of  IFRS  1 and  has  applied  IFRS  3 to  business
combinations  from August 2003,  freezing the existing UK GAAP goodwill balances
at their January 1, 2004 levels for acquisitions before that date.

i) ACQUISITION OF ACAMBIS INC.
During 1999, Acambis acquired Acambis Inc. Under superseded UK GAAP,  in-process
R&D did not meet the criteria for  recognition  as a separate  intangible  asset
and, thus, such amounts were subsumed within  goodwill.  As permitted under IFRS
transition rules, Acambis elected not to restate goodwill for acquisitions prior
to August 2003.  Therefore  the IFRS  goodwill  relating to Acambis Inc. has not
been  restated  and is based on the UK GAAP value of the  goodwill  at 1 January
2004, and is deemed a sterling  denominated  asset. Under US GAAP at the date of
acquisition, in accordance with APB Opinion No. 16, 'Business Combinations', and
No.  17,  'Intangible  Assets',  in-process  R&D is  separately  identified  and
analyzed  to  determine  the  fair  market  value  at the  date of  acquisition.
In-process R&D is identified in accordance with the definition  within Statement
of  Financial  Accounting  Standard  (SFAS) No.2,  'Accounting  for Research and
Development Costs'.  Following  identification of qualifying R&D projects within
Acambis Inc,  their value was  determined by estimating the costs to develop the
purchased  in-process  R&D into  commercially  viable  products,  estimating the
resulting net cash flows from the projects and discounting the net cash flows to
their present value.

As a result of the valuation of in-process  R&D under US GAAP, the fair value of
assets  acquired is  different  from that  calculated  under IFRS,  resulting in
differing  values of goodwill.  Under US GAAP,  in-process R&D is written off to
the income statement when incurred.

ii) ACQUISITION OF BERNA PRODUCTS CORPORATION (BPC)
In August  2003,  Acambis  acquired  BPC, a sales,  promotion  and  distribution
organization  based in Miami,  US and  Toronto,  Canada in order to enhance  the
marketing function of the Group.

The  consideration  paid  for BPC  includes  amounts  contingent  on the  future
performance of that organization.  Under IFRS, a reasonable estimate of the fair
value of amounts expected to be payable in the future is included in the cost of
the  acquisition  and such amounts are  re-assessed at each reporting  date. The
fair  value  of  contingent  consideration  payable  in cash is  taken to be the
estimated  amount of cash payable  discounted to its present value. The discount
is unwound through the income statement so that the full liability is recognized
at the time it is due to be paid.  Under US GAAP,  contingent  consideration  is
recognized  when the  contingency  is resolved,  and the  consideration  becomes
payable.  Accordingly,  contingent  consideration  paid in  2004  and  2005  was
recognized at that time.

iii) AMORTIZATION OF GOODWILL AND INTANGIBLES
As under US GAAP,  IFRS goodwill is not  systematically  amortized,  but is also
reviewed  annually  for  impairment.  Intangible  assets  acquired  as part of a
business combination are amortized under US GAAP and IFRS. The annual impairment
review carried out this year did not reveal any indication of impairment.

g) CAPITALIZATION OF INTEREST
Under IFRS, Acambis'  accounting policy is that interest is not capitalized.  US
GAAP requires interest incurred as part of the cost of constructing fixed assets
to be capitalized and amortized over the life of the asset.

h) AVAILABLE FOR SALE INVESTMENTS
Under US GAAP, investments in available-for-sale securities are marked to market
where the market  value is readily  determinable  and gains and  losses,  net of
deferred  taxation,  are  recorded  in 'Other  comprehensive  income'.  Where an
impairment  is considered  to be other than  temporary,  the security is written
down through the income  statement to a new cost basis  represented  by the fair
value of the security on the date the impairment was determined. Under IFRS, the
Group's accounting policy is to carry such investments at market value, with the
movement net of deferred tax recorded though the 'Statement of recognised income
and expense'. The basis for determining a readily available market value differs
between  US GAAP and IFRS,  such  that,  under US GAAP,  no  revaluation  of the
group's unlisted investment has been recorded.

i) RESTRICTED CASH
US GAAP requires that any cash that is restricted as to its use be excluded from
cash and cash  equivalents.  Acambis has escrow bank accounts of GBP0.7m  (2004:
GBP0.4m)  that meet the  restriction  criteria.  If  Acambis  reported a US GAAP
balance sheet, these would appear separately on that balance sheet.

j) DEFERRED TAX
Under IAS 12 'Income taxes' deferred tax is provided on a full liability method,
on all temporary  differences at the balance sheet date between the tax bases of
assets and  liabilities  and their  carrying  amounts  for  financial  reporting
purposes.  Under US GAAP,  SFAS 109 'Deferred tax' deferred tax is provided on a
full liability basis.  Future tax benefits are recognized as deferred tax assets
to the extent that their  realization  is more likely than not as  determined by
the evaluation of certain criteria.

k) IN-PROCESS R&D
Under IAS 38  'Intangible  assets' it is  necessary to  capitalise  any acquired
in-process R&D.  Amortisation  commences once the acquired technology is brought
into use. Un-amortised amounts are subject to impairment reviews annually and on
occurrence of a trigger event. Under US GAAP acquired in-process R&D is expensed
immediately to the income statement.

l) CAPITALIZED SOFTWARE
Under IFRS,  computer  software used in the group is classified as an intangible
asset.  Under US GAAP, such computer software is classified as a tangible asset.
There  is no  impact  on  shareholders'  equity.  At the end of 2005  there  was
software with a carrying value of GBP0.3m (2004 - GBP0.3m).

RECONCILIATION OF NET (LOSS)/PROFIT FROM IFRS TO US GAAP
Based  on  the  differences  detailed  above,  the  following  table  shows  the
reconciliation of the Group's net (loss)/profit for the past two years:




                                                                                                

                                                                                           Year ended Dec 31

                                                                                          2005          2004

                                                                            Notes         GBPm          GBPm
_____________________________________________________________________________________________________________
Net (loss)/profit as reported under IFRS                                                (27.0)          19.7
Adjustments for:
Revenue recognition                                                        a,b,c           8.9          17.0
Inventory subject to deferred revenue arrangements                            b              -           0.3
Recognition of costs previously deferred                                      b          (0.3)         (9.4)
Other income relating to license fees                                         c          (0.4)             -
Compensation costs under variable plan accounting for share options and       e            1.2           0.1
SAYE plan discount
Purchase price accounting adjustments                                         f            0.1           0.1
Depreciation and impairment of capitalized interest                           g          (0.2)         (0.2)
Capitalization of interest                                                    g            0.5             -
Available for sale investments                                                h              -           0.5
In-process R&D                                                                k          (0.4)             -
Net tax effect of US GAAP adjustments                                         d          (2.7)         (4.5)
_____________________________________________________________________________________________________________
Net (loss)/profit as reported under US GAAP                                             (20.3)          23.6
_____________________________________________________________________________________________________________

 (LOSS)/PROFIT PER SHARE UNDER US GAAP
                                                                         Year ended Dec 31

                                                                          2005        2004
__________________________________________________________________________________________
Basic (loss)/profit per ordinary share in pence                         (18.9)       22.2

Shares used in computing basic (loss)/profit per ordinary share   107,211,367   106,300,080
___________________________________________________________________________________________
Diluted (loss)/profit per ordinary share in pence                       (18.9)         21.7

Shares used in computing diluted (loss)/profit per ordinary share 107,211,367   108,649,389
___________________________________________________________________________________________
Anti-dilutive securities                                            2,474,352      942,032

__________________________________________________________________________________________

OTHER COMPREHENSIVE INCOME
In  addition  to the net loss for the year,  there is also  other  comprehensive
income  relating to foreign  currency  gains,  which amounted to GBP2.6m (2004 -
loss of GBP2.8m).

RECONCILIATION OF SHAREHOLDERS' EQUITY FROM IFRS TO US GAAP
                                                                                                As at Dec 31
                                                                                         2005           2004
                                                                          Notes         GBPm             GBPm
_____________________________________________________________________________________________________________
Shareholders' equity as reported under IFRS                                              83.0          107.5
Revenue recognition                                                      a,b,c            3.1          (5.5)
Inventory subject to deferred revenue arrangements                         b                -            0.3
Goodwill of Acambis Inc.                                                   f            (7.6)          (8.2)
Goodwill of BPC                                                            f              0.3          (1.3)
Contingent consideration                                                   f                -            1.4
Capitalization of interest                                                 g              0.8            0.5
Available for sale investments                                             h            (0.2)              -
In-process R&D                                                             k            (0.4)              -
Net tax effect of US GAAP adjustments                                      d            (0.8)            1.6
_____________________________________________________________________________________________________________
Shareholders' equity as reported under US GAAP                                           78.2           96.3
_____________________________________________________________________________________________________________




RECENT ACCOUNTING PRONOUNCEMENTS

US GAAP

In November 2004,  the FASB issued FASB Statement No. 151 'Inventory  Costs - An
Amendment of ARB No. 43, Chapter 4' ('FAS 151').  FAS 151 amends the guidance in
ARB No. 43,  Chapter 4  'Inventory  Pricing,'  to  clarify  the  accounting  for
abnormal amounts of idle facility expense,  freight,  handling costs, and wasted
material  (spoilage).  Among other provisions,  the new rule requires that items
such  as  idle  facility  expense,   excessive  spoilage,  double  freight,  and
re-handling costs be recognized as current-period  charges regardless of whether
they meet the criterion of 'so abnormal' as stated in ARB No. 43.  Additionally,
FAS 151 requires that the allocation of fixed production  overheads to the costs
of conversion be based on the normal capacity of the production facilities.  FAS
151 is effective for fiscal years beginning after June 15, 2005.


The Group will adopt FAS 151 in 2006 but does not expect the adoption of the new
standard to have a material impact.


In  December  2004,  the FASB  issued  FASB  Statement  No.  153  'Exchanges  of
Nonmonetary  Assets  - An  Amendment  of APB  Opinion  No.  29,  Accounting  for
Nonmonetary  Transactions'  ('FAS 153').  FAS 153  eliminates the exception from
fair value measurement for non monetary  exchanges of similar  productive assets
in  paragraph  21(b)  of  APB  Opinion  No.  29,   'Accounting  for  Nonmonetary
Transactions,'  and replaces it with an exception for exchanges that do not have
commercial  substance.  FAS  153  specifies  that a  non-monetary  exchange  has
commercial  substance  if the future  cash flows of the entity are  expected  to
change  significantly as a result of the exchange.  FAS 153 is effective for the
fiscal  periods  beginning  after June 15, 2005. The Group will adopt FAS 153 in
2006 but does not expect the  adoption  of the new  standard  to have a material
impact.


In  December  2004,  the FASB  issued  FASB  Statement  No. 123  (revised  2004)
'Share-Based Payment' ('FAS 123(R)'), which replaces FAS No. 123 'Accounting for
Stock-Based  Compensation'  ('FAS  123')  and  supersedes  APB  Opinion  No.  25
'Accounting  for Stock Issued to Employees.' FAS 123(R) requires all share-based
payments  to  employees,  including  grants of  employee  stock  options,  to be
recognized in the financial statements based on their fair values beginning with
the first  interim or annual  period  after June 15, 2005,  with early  adoption
encouraged.  The pro forma  disclosures  previously  permitted  under FAS 123 no
longer will be an alternative to financial statement  recognition.  The Group is
currently assessing the impact of FAS 123(R).


In March 2005,  the FASB  issued  FASB  Interpretation  No. 47  'Accounting  for
Conditional  Asset Retirement  Obligations - an interpretation of FASB Statement
No. 143' ('FIN 47').  FIN 47 clarifies the timing of liability  recognition  for
legal obligations  associated with the retirement of a tangible long-lived asset
when the timing and/or  settlement are conditional on a future event.  FIN 47 is
effective for the fiscal periods ending after December 15, 2005. The adoption of
FIN 47 did not have a material impact on the Group.


In May 2005, the FASB issued  Statement No. 154,  'Accounting  Changes and Error
Corrections  - A  replacement  of APB Opinion No. 20 and FASB  Statement  No. 3'
('FAS 154'). This statement requires retrospective application to prior periods'
financial   statements  of  changes  in  accounting   principles  unless  it  is
impracticable to determine either the period-specific  effects or the cumulative
effect of the  change.  This  statement  applies  to all  voluntary  changes  in
accounting  principles and changes required by an accounting  pronouncement that
does not  include  specific  transition  provisions.  FAS 154 is  required to be
adopted in fiscal years  beginning  after  December 15, 2005.  FAS 154 would not
have had a material effect on the financial  position,  results of operations or
cash flows of the Group under US GAAP as at December 31, 2005.


In October 2005, the FASB issued FASB Staff Position (FSP) 13-1  'Accounting for
Rental Costs  Incurred  during a  Construction  Period' ('FSP  13-1').  FSP 13-1
requires rental costs  associated with ground or building  operating leases that
are incurred during a construction period to be recognized as rental expense and
included in income from  continuing  operations.  FSP 13-1 is effective  for the
fiscal periods  beginning after December 15, 2005. The Group will adopt FSP 13-1
in 2006 but does not expect the  adoption of the new standard to have a material
impact.


In January 2006 the FASB issued FASB Statement No. 155  'Accounting  for Certain
Hybrid Financial  Instruments - an amendment of FASB Statements No. 133 and 140'
('FAS 155').  FAS 155 provides  entities  with relief from having to  separately
determine  the fair value of an  embedded  derivative  that would  otherwise  be
required to be bifurcated  from its host contract.  FAS 155 is effective for all
financial  instruments  acquired,  issued or subject to a  re-measurement  event
occurring after the beginning of an entity's first fiscal year that begins after
September 15, 2006. The Group is currently evaluating the impact the adoption of
FAS 155 will have, but does not expect it to have a material impact.



Item 19. Exhibits
Exhibit
Number     Description of Exhibit


12.1        Section 302 Certification of Gordon Cameron.

12.2        Section 302 Certification of Elizabeth Brown.

13.1       Certification of Gordon Cameron pursuant to 18 U.S.C. Section 1350,
           as adopted by Section 906 of the Sarbanes-Oxley Act of 2002.

13.2       Certification of Elizabeth Brown pursuant to 18 U.S.C. Section 1350,
           as adopted by Section 906 of the Sarbanes-Oxley Act of 2002.

15.1       Consent of PricewaterhouseCoopers LLP.


                                    SIGNATURES


The registrant hereby certifies that it meets all of the requirements for filing
on Form 20-F and that it has duly caused and authorized the  undersigned to sign
this Amendment No. 1 to its annual report for its fiscal year ended December 31,
2005 on its behalf.

                                          ACAMBIS PLC

                                          By:    /s/ Elizabeth Brown

                                          Name:  Elizabeth Brown
                                          Title: Acting Chief Financial Officer


Date: April 3, 2007



                                              EXHIBIT INDEX
Exhibit
Number Description of Exhibit

12.1    Section 302 Certification of Gordon Cameron.

12.2    Section 302 Certification of Elizabeth Brown.

13.1   Certification of Gordon Cameron pursuant to 18 U.S.C. Section 1350, as
       adopted by Section 906 of the Sarbanes-Oxley Act of 2002.

13.2   Certification of Elizabeth Brown pursuant to 18 U.S.C. Section 1350, as
       adopted by Section 906 of the Sarbanes-Oxley Act of 2002.

15.1   Consent of PricewaterhouseCoopers LLP.



                                                                   Exhibit 12.1


                                              Certifications
I, Gordon Cameron, certify that:
1.  I have reviewed this amendment to the annual report on Form 20-F of Acambis
    plc;

2.   Based on my knowledge, this report does not contain any untrue statement of
     a material  fact or omit to state a  material  fact  necessary  to make the
     statements made, in light of the circumstances  under which such statements
     were made,  not  misleading  with  respect  to the  period  covered by this
     report;

3.   Based on my  knowledge,  the  financial  statements,  and  other  financial
     information  included  in  this  report,  fairly  present  in all  material
     respects the financial  condition,  results of operations and cash flows of
     the company as of, and for, the periods presented in this report;

4.   The  company's  other   certifying   officer  and  I  are  responsible  for
     establishing and maintaining disclosure controls and procedures (as defined
     in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the company and have:

      (a) Designed  such disclosure  controls and procedures,  or caused such
          disclosure controls and procedures to be designed under our
          supervision, to ensure that  material  information  relating to the
          company,  including its consolidated  subsidiaries,  is made  known to
          us by  others  within  those entities,  particularly  during the
          period in which  this  report is being prepared;

     (b) Evaluated the  effectiveness of the company's  disclosure  controls
         and  procedures  and  presented  in this report our  conclusions  about
         the effectiveness of the disclosure  controls and procedures,  as of
         the end of the period covered by this report based on such evaluation;
         and

     (c) Disclosed  in this  report  any  change in the  company's  internal
         control over financial reporting that occurred during the period
         covered by the annual report that has materially affected,  or is
         reasonably likely to materially affect, the company's internal control
         over financial reporting;  and

5.   The company's other certifying  officer and I have disclosed,  based on our
     most recent evaluation of internal control over financial reporting, to the
     company's  auditors  and the  audit  committee  of the  company's  board of
     directors (or persons performing the equivalent functions):

     (a) All significant  deficiencies and material weaknesses in the design
        or  operation  of  internal  control  over  financial  reporting  which
        are reasonably  likely to  adversely  affect the  company's  ability to
        record, process, summarize and report financial information; and

    (b)  Any  fraud,  whether or not material,  that involves  management or
         other  employees  who have a  significant  role in the  company's
         internal control over financial reporting.



Date: April 3, 2007             By:      /S/ Gordon Cameron
                               Name:    Gordon Cameron
                               Title:   Chief Executive Officer




                                                                   Exhibit 12.2
                                 Certifications

I, Elizabeth Brown, certify that:
1.  I have reviewed this amendment to the annual report on Form 20-F of Acambis
    plc;

2.   Based on my knowledge, this report does not contain any untrue statement of
     a material  fact or omit to state a  material  fact  necessary  to make the
     statements made, in light of the circumstances  under which such statements
     were made,  not  misleading  with  respect  to the  period  covered by this
     report;

3.   Based on my  knowledge,  the  financial  statements,  and  other  financial
     information  included  in  this  report,  fairly  present  in all  material
     respects the financial  condition,  results of operations and cash flows of
     the company as of, and for, the periods presented in this report;

4.   The  company's  other   certifying   officer  and  I  are  responsible  for
     establishing and maintaining disclosure controls and procedures (as defined
     in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the company and have:

     (a)Designed  such  disclosure  controls  and  procedures,  or  caused  such
        disclosure  controls and  procedures to be designed  under our
        supervision, to ensure  that  material  information  relating  to  the
        company, including  its consolidated subsidiaries,  is made known to us
        by others within those entities, particularly during the period in which
        this report is being prepared;

     (b)Evaluated  the  effectiveness  of  the  company's   disclosure
        controls and procedures  and presented in this report our  conclusions
        about the effectiveness of the disclosure controls and procedures,  as
        of the  end of the  period  covered  by  this  report  based  on  such
          evaluation; and

     (c)Disclosed in this report any change in the company's  internal
        control  over  financial  reporting  that  occurred  during the period
        covered by the  annual  report  that has  materially  affected,  or is
        reasonably likely to materially affect, the company's internal control
        over financial reporting; and

5.   The company's other certifying  officer and I have disclosed,  based on our
     most recent evaluation of internal control over financial reporting, to the
     company's  auditors  and the  audit  committee  of the  company's  board of
     directors (or persons performing the equivalent functions):

     (a)All  significant  deficiencies and material  weaknesses in the
          design or operation of internal control over financial reporting which
          are  reasonably  likely to adversely  affect the company's  ability to
          record, process, summarize and report financial information; and

      (b)Any fraud,  whether or not material,  that involves management
          or  other  employees  who  have a  significant  role in the  company's
          internal control over financial reporting.





Date: April 3, 2007             By:      /s/ Elizabeth Brown
                               Name:    Elizabeth Brown
                               Title:   Acting Chief Financial Officer



                                                                   Exhibit 13.1


                                       CERTIFICATION
                           PURSUANT TO 18 U.S.C. SECTION 1350,
          AS ADOPTED BY SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Gordon Cameron,  as Chief Executive  Officer of Acambis plc (the  "Company"),
hereby certify,  pursuant to 18 U.S.C. Ss 1350, as adopted by Section 906 of the
Sarbanes-Oxley Act of 2002, that to my knowledge:

(1) the  accompanying  amendment to the Annual  Report on Form 20-F for the year
ended  December  31,  2005,  as  filed  with the U.S.  Securities  and  Exchange
Commission (the "Report"), fully complies with the requirements of Section 13(a)
or 15(d), as applicable, of the Securities Exchange Act of 1934, as amended; and

(2) the  information  contained in the Annual  Report  fairly  presents,  in all
material  respects,  the  financial  condition  and results of operations of the
Company.




Date: April 3, 2007             By:      /s/ Gordon Cameron
                               Name:    Gordon Cameron
                               Title:   Chief Executive Officer

A signed  original of this  written  statement  required by Section 906 has been
provided to Acambis plc and will be retained by Acambis plc and furnished to the
Securities and Exchange Commission or its staff upon request.



                                                                  Exhibit 13.2


                                  CERTIFICATION
                       PURSUANT TO 18 U.S.C. SECTION 1350,
           AS ADOPTED BY SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Elizabeth  Brown, as Chief Financial  Officer of Acambis plc (the "Company"),
hereby certify,  pursuant to 18 U.S.C. Ss 1350, as adopted by Section 906 of the
Sarbanes-Oxley Act of 2002, that to my knowledge:

(1) the  accompanying  amendment to the Annual  Report on Form 20-F for the year
ended  December  31,  2005,  as  filed  with the U.S.  Securities  and  Exchange
Commission (the "Report"), fully complies with the requirements of Section 13(a)
or 15(d), as applicable, of the Securities Exchange Act of 1934, as amended; and

(2) the  information  contained in the Annual  Report  fairly  presents,  in all
material  respects,  the  financial  condition  and results of operations of the
Company.




Date: April 3, 2007             By:      /s/ Elizabeth Brown
                               Name:    Elizabeth Brown
                               Title:   Acting Chief Financial Officer

A signed  original of this  written  statement  required by Section 906 has been
provided to Acambis plc and will be retained by Acambis plc and furnished to the
Securities and Exchange Commission or its staff upon request.




                                                                    Exhibit 15.1





            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


We  hereby  consent  to the  incorporation  by  reference  in  the  Registration
Statement on FormS-8 (No. 333-78277, No.333-100028, No.333-109577, No.333-137759
and  No.333-140540) of Acambis plc of our report dated June 26, 2006 relating to
the financial  statements which appear in this amendment to the Annual Report on
Form20-F for the year ended December31, 2005.


/s/ PricewaterhouseCoopers LLP


PricewaterhouseCoopers LLP
Cambridge, England
April 3, 2007




                                      SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant Peptide Therapeutics Group has duly caused this report to be
signed on its behalf by the undersigned, thereunto duly authorized.



Date: 03 April 2007                              ACAMBIS PLC


                                        By:  /s/ Lyndsay Wright
                                             Name: Lyndsay Wright
                                             Title: VP, Communications and IR.