Director shareholding

Cambridge, UK - 23 June 2003 - Acambis plc ("Acambis") (LSE: ACM, NASDAQ: ACAM)
announces a transaction involving an increase in a director's shareholding in
Acambis.

On 23 June 2003, Dr John Brown, Chief Executive Officer, exercised options over
a total of 16,681 shares at 180p per share. At the same time, he sold 12,300 of
these shares at 361p per share in order to fund the cost of exercising the
options and to satisfy the taxation liabilities arising from share option
exercises. Following these transactions, Dr Brown's shareholding in Acambis
increased from 479,746 to 484,127 shares representing approximately 0.46% of
Acambis' issued ordinary share capital, of which 4,648 shares are held by the
Trustees of Acambis Employees' Trust on behalf of Dr Brown.

                                    -ends-                                     

Enquiries:

Acambis plc                                                                    
                                                                               
Lyndsay Wright, Director of              Tel: +44 (0) 1223 275 300             
Communications                                                                 
                                                                               



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