Safety and immunogenicity of Chiron/Biocine(R) recombinant acellular pertussis-diphtheria-tetanus vaccine in infants and toddlers

Objective. To evaluate the safety and immunogenicity of the recombinant acellular pertussis diphtheria-tetanus (aPDT) vaccine (C-aPDT, Chiron/Biocines(R)). Study design. This is a randomized blinded trial evaluating the safety and immunogenicity of the recombinant aPDT vaccine (C-aPDT, Chiron/Biocine(R)) in 2000 infant recipients compared with 498 controls who received whole cell diphtheria-pertussis-tetanus (wDPT; Connaught) vaccine at 2, 4 and 6 months of age. In addition the safety and immunogenicity of the same C-aPDT vaccine were evaluated as a booster dose in a subset of the same population when given at 15 to 18 months of age and compared with licensed Lederle aPDT vaccine. Results. The C-aPDT vaccine was associated with very few local or systemic reactions when compared with wDPT. In toddlers the local and systemic side effects observed were similar after either acellular vaccine. When the immunogenicity of the C-aPDT vaccine was compared with the wDPT (Connaught) in infancy, the vaccines were equivalent for anti-diphtheria response, the wDPT developed higher anti-tetanus response and the C-aPDT vaccine was significantly more immunogenic for all other antigens tested. In toddlers the C-aPDT acellular vaccine exhibited equal or improved immunogenicity for antigens tested as compared with Lederle aPDT except for a higher anti-filamentous hemagglutinin response with the Lederle aPDT vaccine. Conclusion. The Chiron/Biocine(R) aPDT vaccine offers an improved safety profile as well as improved immunogenicity when compared with a licensed wDPT product.