Clinical and Serological Responses to Plague Vaccine U.S.P.

Abstract

Abstract : Twenty-nine volunteers were administered a basic inoculation and two booster doses of plague vaccine. Reactogenicity was determined following each dose of vaccine, and sera for serological tests were collected at selected intervals over a period of 390 days. The vaccine was found to be of low reactogenicity. Thirty days after the initial dose of vaccine, 86 per cent of the subjects produced detectable HA antibodies. Subsequent booster doses of vaccine stimulated increased production of HA antibody, which persisted longer with each successive dose. Individuals developing an HA antibody titer of 1:128 or greater had MPI values of 10 or less. CF antibody in low titer developed following the first and second booster doses of vaccine in 19 per cent and 17 per cent.