Infant immunization with pneumococcal CRM sub(197) vaccines: Effect of saccharide size on immunogenicity and interactions with simultaneously administered vaccines

• Published in: The Journal of infectious diseases 1997-08, Vol.176 (2), p.445-455
• Main Authors: Daum, R S, Hogerman, D, Rennels, M B, Bewley, K, Malinoski, F, Rothstein, E, Reisinger, K, Block, S, Keyserling, H, Steinhoff, M
• Format: Article
• Language: English
• Subjects: Streptococcus pneumoniae
• ISSN: 0022-1899

Six pentavalent pneumococcal conjugate vaccines (Pn-CRM sub(197)) were evaluated among 400 infants. The vaccines differed in saccharide chain length (oligosaccharide [OS] or polysaccharide [PS]) and saccharide quantity (0.5, 2, or 5 mu g). Subjects were randomized into groups 1-6 (Pn-CRM sub(197) recipients) or 7 (controls) for immunization at 2, 4, and 6 months of age. Pn-CRM sub(197) were well tolerated and elicited mean antibody concentrations that exceeded those in controls for all 5 capsular serotypes. PS formulations were generally more immunogenic than their OS counterparts. For PS vaccines, a dose-response was documented (5 mu g > 2 mu g > 0.5 mu g), but the differences between the 5- and 2- mu g formulations were insignificant. The mean anti-PRP antibody concentration was significantly higher among Pn-CRM sub(197) recipients. It is concluded that PS vaccines are more immunogenic than OS vaccines. The improved immunogenicity from Haemophilus type b oligosaccharide conjugate (HbOC) vaccine when given with Pn-CRM sub(197) suggests that a decreased dose of HbOC vaccine may be sufficient to elicit protection.