Statement re BTG

Cambridge, UK and Cambridge, Massachusetts - 24 October 2003 - Acambis plc
("Acambis") (LSE: ACM, NASDAQ: ACAM) announces that it has agreed a settlement
with BTG International Limited ("BTG") concerning payments due under an
Assignment Consideration Agreement ("the Agreement"). Signed in 1997, the
Agreement relates to a technology license agreement between Acambis and BTG
originally established in 1994. The Agreement provided for Acambis to pay 2% of
its reported turnover to BTG potentially until 2024.

Under the terms of the settlement, Acambis will pay �12m to BTG to discharge
all past and future rights, obligations and claims under the Agreement.

Of the settlement payment, Acambis estimates �4.6m relates to historic amounts
due and payable under the Agreement since January 2002 when discussions between
Acambis and BTG about the Agreement were initiated. The balance of �7.4m
relates to potential future payments from the fourth quarter ("Q4") of 2003
onwards. Acambis will book the �7.4m balance during Q4 2003 as an exceptional
item against operating profit. The full payment will be made from cash before
the end of 2003.

Acambis had accrued for 100% of the potential costs relating to the Agreement
between January 2002 and the end of September 2003, recording these within cost
of sales. In addition, it had factored in the full potential liability in its
future margin and earnings guidance. This 2% payment was factored into Acambis'
guidance on gross operating margins. As a result of the termination of the
Agreement, gross margins are expected to improve by approximately 2% from 2004
onwards, as compared to previous guidance.

                                    -ends-                                     

Enquiries:

Acambis plc                                                                    
                                                                               
Dr John Brown, Chief Executive Officer   Tel: +44 (0) 1223 275 300             
                                                                               
Lyndsay Wright, Director of                                                    
Communications                                                                 
                                                                               
Gordon Cameron, Chief Financial Officer  Tel: +1 (617) 761 4200                
                                                                               
Financial Dynamics                                                             
                                                                               
David Yates/Jonathan Birt                Tel: +44 (0) 20 7831 3113             

Notes to editors:

Acambis is a leading developer of vaccines to prevent and treat infectious
diseases. Recognised internationally as the leading producer of smallpox
vaccines, Acambis is developing a second-generation smallpox vaccine which is
currently undergoing clinical trials and, under a unique arrangement given the
threat of smallpox being used as a bioterrorist weapon, is manufacturing
emergency-use stockpiles of this investigational vaccine for the US Government
and other governments around the world. Acambis is establishing a travel
vaccines franchise through its US-based subsidiary Berna Products Corporation,
which markets Vivotif�, the world's only single dose oral typhoid vaccine, in
North America. Acambis has a number of other potential travel vaccines in
development and is conducting clinical trials of vaccines against yellow fever,
Japanese encephalitis and dengue fever. Acambis is also preparing to start
clinical trials of a vaccine targeting the West Nile virus, which has spread to
45 US States in the last four years.

Acambis is based in Cambridge, UK and Cambridge, Massachusetts, US. Its primary
listing is on the London Stock Exchange (ACM) and its shares are listed in the
form of American Depositary Receipts on Nasdaq (ACAM). More information is
available at www.acambis.com.

"Safe Harbor" statement under the Private Securities Litigation Reform Act of
1995:

The statements in this news release that are not historical facts are
forward-looking statements that involve risks and uncertainties, including the
timing and results of clinical trials, product development, manufacturing and
commercialisation risks, the risks of satisfying the regulatory approval
process in a timely manner, the need for and the availability of additional
capital. For a discussion of these and other risks and uncertainties see "Risk
factors" in the Company's Annual Report and Form 20-F for the most recently
ended fiscal year, in addition to those detailed in the Company's filings made
with the Securities and Exchange Commission from time to time. These
forward-looking statements are based on estimates and assumptions made by the
management of Acambis and are believed to be reasonable, though are inherently
uncertain and difficult to predict. Actual results or experience could differ
materially from the forward-looking statements.



END