Yersinia pestis vaccine

Patent Pending A formalin-inactivated vaccine once was available in the United States for adults at high risk of contracting the plague until removal from the market by the U.S. Food and Drug Administration. It was of limited effectiveness and could cause severe inflammation. Experiments with genetic engineering of a vaccine based on F1 and V antigens are underway and show promise. However, bacteria lacking antigen F1 are still virulent, and the V antigens are sufficiently variable, such that vaccines composed of these antigens may not be fully protective.