Not for release, publication or distribution, in whole or in part, in or into or from Canada, Australia, New Zealand, South Africa or Japan or any other jurisdiction where to do so would constitute a violation of the relevant laws or regulations of such jurisdiction.

9 August 2008

Recommended acquisition of Acambis plc ('Acambis') 

by Sanofi Pasteur Holding ('Sanofi Pasteur') 

by way of scheme of arrangement

Posting of Scheme Document 

On 25 July 2008, Sanofi Pasteur and Acambis announced that they had reached agreement on the terms of a recommended cash offer for the entire issued and to be issued share capital of Acambis by Sanofi Pasteur (the 'Acquisition'). The Acquisition will be implemented by way of a Court sanctioned scheme of arrangement under Part 26 of the Companies Act 2006 (the 'Scheme'). 

The Scheme Document, which sets out, amongst other things, the full terms and conditions of the Scheme and an explanatory statement, together with the action to be taken by Acambis Shareholders, was posted to Acambis Shareholders on 9 August 2008.

Notices convening the Court Meeting and the General Meeting to be held at the offices of Morrison & Foerster, 7th Floor, CityPoint, One Ropemaker Street, London EC2Y 9AW, at 10.00 a.m. and 10.30 a.m., respectively, on 2 September 2008 (or, with respect to the General Meeting, as soon thereafter as the Court Meeting is concluded or adjourned) are contained in the Scheme Document. Subject to the satisfaction or waiver of the Conditions to the Scheme, it is expected that the Scheme will become effective on 25 September 2008. If any of the expected dates change, Acambis will give notice of the change by issuing an announcement through a Regulatory Information Service.

It is expected that the last day of dealings in Acambis Shares will be 23 September 2008 and that trading of Acambis Shares on the main market for listed securities of the London Stock Exchange will be cancelled with effect from 26 September 2008.

Copies of the Scheme Document will be available for inspection during normal business hours on any business day at the offices of Morrison & Foerster, 7th Floor, CityPoint, One Ropemaker Street, London EC2Y 9AW, up to and including the date on which the Scheme becomes effective in accordance with its terms.

Unless the context otherwise requires, terms defined in the announcement dated 25 July 2008 have the same meaning in this announcement. 

Enquiries:

The directors of Acambis accept responsibility for the information contained in this announcement. To the best of the knowledge and belief of the directors of Acambis (who have taken all reasonable care to ensure that such is the case), the information contained in this announcement is in accordance with the facts and does not omit anything likely to affect the import of such information. 

Goldman Sachs International, which is authorised and regulated in the UK by the Financial Services Authority, is acting exclusively for Acambis and no one else in connection with the Proposals and will not be responsible to anyone other than Acambis for providing the protections afforded to clients of Goldman Sachs International nor for providing advice in connection with the Proposals or any matter referred to in this announcement.  

Morgan Stanley & Co Limited is acting exclusively for Sanofi Pasteur and sanofi-aventis and no one else in connection with the Proposals and will not be responsible to anyone other than Sanofi Pasteur and sanofi-aventis for providing the protections afforded to clients of Morgan Stanley & Co Limited nor for providing advice in connection with the Proposals or any matter referred to in this announcement.

This announcement, including information included or incorporated by reference in this announcement, may contain 'forward-looking statements' concerning Sanofi Pasteur and Acambis. Generally, the words 'will', 'may', 'should', 'continue', 'believes', 'expects', 'intends', 'anticipates' or similar expressions identify forward-looking statements. The forward-looking statements involve risks and uncertainties that could cause actual results to differ materially from those expressed in the forward-looking statements. Many of these risks and uncertainties relate to factors that are beyond the companies' abilities to control or estimate precisely, such as future market conditions and the behaviours of other market participants, and therefore undue reliance should not be placed on such statements. Sanofi Pasteur and Acambis assume no obligation and do not intend to update these forward-looking statements, except as required pursuant to applicable law.

Dealing disclosure requirements

Under the provisions of Rule 8.3 of the City Code, if any person is, or becomes, 'interested' (directly or indirectly) in 1% or more of any class of 'relevant securities' of Acambis, all 'dealings' in any 'relevant securities' of Acambis (including by means of an option in respect of, or a derivative referenced to, any such 'relevant securities') must be publicly disclosed by no later than 3.30pm (London time) on the Business Day following the date of the relevant transaction. This requirement will continue until the Scheme becomes effective or the offer lapses or is otherwise withdrawn or the date on which the 'offer period' otherwise ends. If two or more persons act together pursuant to an agreement or understanding, whether formal or informal, to acquire an 'interest' in 'relevant securities' of Acambis, they will be deemed to be a single person for the purpose of Rule 8.3 of the City Code.

Under the provisions of Rule 8.1 of the City Code, all 'dealings' in 'relevant securities' of Acambis by Acambis or Sanofi Pasteur, or by any of their respective 'associates' must be disclosed by no later than 12.00 noon (London time) on the Business Day following the date of the relevant transaction.

A disclosure table, giving details of the companies in whose 'relevant securities' 'dealings' should be disclosed, and the number of such securities in issue, can be found on the Panel's website at www.thetakeoverpanel.org.uk.

'Interests in securities' arise, in summary, when a person has long economic exposure, whether conditional or absolute, to changes in the price of securities. In particular, a person will be treated as having an 'interest' by virtue of the 'ownership' or control of securities, or by virtue of any option in respect of, or derivative referenced to, securities.

Terms in quotation marks are defined in the City Code, which can also be found on the Panel's website. If you are in any doubt as to whether or not you are required to disclose a 'dealing' under Rule 8, you should consult the Panel.