Reactivity and antibody responses of volunteers given two or three doses of pneumococcal vaccine.

Abstract

Pneumococcal antibody responses and adverse reactions were assessed in 12 healthy volunteers who received either two (10 volunteers) or three (2 volunteers) doses of pneumococcal polysaccharide vaccines at 1 or 2 year intervals. The volunteers were given hexavalent (types 1, 3, 4, 7F, 8, 12F) octavalent (types 14, 19F added) nonavalent (type 5 added), and tridecavalent (types 6A, 6B, 9N, 18C, 23F added; type 5 removed) pneumococcal vaccines. Local and systemic reactions following any of the vaccines, either first, second, or third doses, were low, and these were mild; fever did not occur. Twelve volunteers received types 1, 3, 4, 7F, 8, and 12F in two doses of vaccine, and four volunteers received types 14 and 19F in two doses of vaccine. Primary immunization induced significant antibody rises to these antigens in most volunteers, but a second dose of vaccine did not further increase antibody levels to the same antigens; when it also contained new antigens, antibody rises usually developed to these antigens. Although the data are limited to detailed studies of only 12 persons, the results suggest that additional studies of this issue would seem appropriate.