Acambis PLC Announces Significant Progress On Its MVA Smallpox Vaccine Programme With Publication Of Phase I Trial Results

Cambridge, UK -- (MARKET WIRE) -- 04/28/2005 -- Cambridge, UK and Cambridge, Massachusetts - 28 April 2005 - Acambis plc (Acambis) (LSE: ACM, NASDAQ: ACAM) announces an update on its programme to develop and manufacture its Modified Vaccinia Ankara ("MVA") attenuated smallpox vaccine, MVA3000, with results from a Phase I clinical trial of MVA3000. Acambis is co-developing the MVA3000 vaccine with Baxter Healthcare SA ("Baxter"), which is providing process development and manufacturing services.