Reactogenicity and immunogenicity of a protein-conjugated pneumococcal oligosaccharide vaccine in older adults

Healthy adults greater than or equal to 50 years old were immunized with either pentavalent Corynebacterium diphtheriae C7 (beta 197) cross-reactive material (CRM(197)) protein-conjugated pneumococcal vaccine (CV) containing 10 mu g each of capsular oligosaccharides from serotypes 6B, 14, 18C, 19F, and 23F or with licensed (23-valent, 25 mu g/serotype) pneumococcal polysaccharide vaccine (PV), Adverse reactions, predominantly local in nature, occurred in 20 of 23 CV recipients versus 13 of 23 PV recipients (P < .05), Compared with mean postvaccination antibody concentrations in PV recipients, those induced by CV were not significantly different for serotypes 6B, 14, 18C, and 23F and were lower for 19F (P < .05). Six months later, reimmunization with PV of subjects who had initially received CV elicited a slight boost in antibody concentrations to levels that were not significantly higher than those achieved after the primary vaccination or than those in persons given a single dose of PV, Pneumococcal vaccines containing protein-conjugated oligosaccharides may offer no advantage over currently licensed preparations containing unconjugated polysaccharides for immunization of healthy older adults.