Pneumococcal vaccine: dose, revaccination, and coadministration with influenza vaccine.

SummaryCurrent pneumococcal vaccine contains 14 specific capsular polysaccharide antigens, each in 50-γg amount. Reduction of dosage to 25 or 12.5 γg per type gave reduced antibody responses in human subjects for most of the serotypes and these were less than current requirements of the U.S. Food and Drug Administration. Specific antibody following vaccination declines slowly and there was no worthwhile increase in antibody on revaccination 1 to 1.5 years following prior vaccination. Reduction in the dosage of antigen to one-half or one-fourth the 50 γg per antigen amount eliminated the enhanced local and systemic reactions noted previously when the full vaccine amount was given but the time interval between vaccination and revaccination was not long enough to test for the ability of the reduced dose to restimulate antibody production. Pneumococcal and influenza virus vaccines given at the same time into opposite arms showed no important reduction in antibody response to either vaccine and there was no in...