Immunogenicity of serogroup A and C Neisseria meningitidis polysaccharide vaccines administered together in humans.

Serogroup A and C Neisseria meningitidis polysaccharide vaccines were administered to U.S. Army recruit volunteers, either two weeks apart or at the same time into two different sites on the same arm, to determine what effect, if any, the combined administration would have on the immunogenicity of each individual component. The vaccines were found to be as immunogenic when administered together as when given separately; in fact, the data suggest a possible enhancement of the response, as measured by the radioactive antigen binding test, to both components when the two vaccines are given together.