Plague is a potentially fatal infection in humans caused by the bacterium Yersinia pestis, transmitted naturally from rodent reservoirs to humans via fleas. Human disease may also result from contact with blood or tissues of infected animals or exposure to aerosolized droplets containing bacteria. Pneumonic plague is typically diagnosed in humans with with high mortality. It has a long history for plague as an agent of biowarfare, and pose a serious threat to international security. In human history, there were three outbreaks of plague all over the world, about 200 million people died from the disease. The increasing trend of plague epidemic in recent years, some regions and countries in the world still has the outbreak of the plague. It implied that safety and safe and effective vaccine is urgently to developing.~Althought the killed whole-cell plague vaccine and live attenuated vaccine has been licensed, these vaccines cause significant adverse reactions, including fever, headache, malaise, lymphadenopathy, erythema and induration at the injection site with high degree of immune variability. They are rarely used today because of toxicities, limited evidence for efficacy to prevent plague, and limited commercial availability. Based on the researches in the last twenty years, it have focused on recombinant subunit vaccines which were formed F1 and V antigens as the main composition provide greater protection than vaccines comprised of either subunit alone. In the primary phase 2a clinical trial, 30μg formulation showed a stronger and sustained immune response. This study was aim to exploring the safety and immunogenicity of a new type plague subunit vaccine which comprised 30μg natural F1 antigen and 30μg recombined V antigen (F1+rV) in two immunization regimens.
Plague is a potentially fatal infection in humans caused by the bacterium Yersinia pestis. Pneumonic plague is typically diagnosed in humans with high mortality. It has a long history for plague as an agent of biowarfare, and pose a serious threat to international security. Althought the killed whole-cell plague vaccine and live attenuated vaccine has been licensed. They are rarely used today because of toxicities, limited evidence for efficacy to prevent plague, and limited commercial availability. In the last twenty years, it have focused on recombinant subunit vaccines which were formed F1 and V antigens as the main composition provide greater protection than vaccines comprised of either subunit alone. This study was aim to exploring the safety and immunogenicity of a new type plague subunit vaccine which comprised natural F1 antigen and recombined V antigen (F1+rV) in two immunization regimens.