A plague vaccine is used for an induction of active specific immunity in a susceptible organism to plague by means of administration an antigenic material (a vaccine) via a variety of routes to people at risk of contracting any clinical form of plague. This method is known as plague immunization. There is strong evidence for the efficacy of administration of some plague vaccines in preventing or ameliorating the effects of a variety of clinical forms of infection by Yersinia pestis. Plague immunization also encompasses incurring state of passive specific immunity to plague in a susceptible organism after administration of a plague serum or plague immunoglobulin in people with an immediate risk of developing the disease.
Many areas that are affected by plague in modern times are third world countries, and therefore cannot get accurate diagnosis or decent medical care for any sufferers of bubonic or pneumonic plague.
A systematic review by the Cochrane Collaboration found no studies of sufficient quality to be included in the review, and were thus unable to make any statement on the efficacy of the vaccine.