Acambis receives US patent for passive C difficile vaccine

In the USA, a patent has been issued to Acambis for its passive vaccineto treat Clostridium difficile-associated diarrhea. The vaccine, which is derived from purified hyperimmune globulin from donors who have been vaccinated with the company's active vaccine against the bacterium, will provide patients with an immune response which their own immune systems would not otherwise be able to generate.

C difficile, an opportunistic antibiotic-resistant bacterium, causes infection when bacteria that normally occur in the gastrointestinal tract are eliminated, often by the use of other antibiotics. The active vaccine against this infection was proven to be immunogenic at all doses studied in a Phase I/II trial, and Acambis is initiating a Phase II efficacy trial with hyperimmune globulin from accredited donors. The company hopes to begin a trial of the passive vaccine next year.