Plague vaccine research and development

A fully recombinant subunit vaccine is described which provides enhanced pr otection against bubonic plague and a new prophylactic against the pneumoni c form of the disease. The vaccine comprises two subunit antigens termed F1 and V which are individually immunogenic and protective and have additive protective effect in combination. The vaccines has been demonstrated effica cious in small animal models, including a strain of mice with a targeted ge ne deletion for interleukin 4 (IL4T mice). The mechanism of protection conf erred by the vaccine is principally antibody-mediated and antibody titre to F1 + V in the mouse correlates with protection. Surrogate markers of effic acy in man have been identified and will be applied to support clinical tri alling of the vaccine. This vaccine could be used to counter bubonic and pn eumonic plague in areas of the world where the disease is endemic.