Safety and immunogenicity of a pentavalent diphtheria, tetanus, pertussis,hepatitis B and polio combination vaccine in infants

Introduction. The objectives of this study were to evaluate the safety and immunogenicity of a new combination vaccine (DTaP-HB-IPV) containing diphth eria, tetanus, acellular pertussis and hepatitis B (HB) and a new inactivat ed poliovirus vaccine (IPV) manufactured by Glaxo-SmithKline (GSK). This va ccine was given in an all IPV or sequential IPV and oral polio vaccine (OPV ) schedule. Another combination vaccine, DTaP-HB (GSK), was similarly evalu ated given with OPV or IPV. Methods. Four hundred infants were randomized into one of four study groups and immunized at 2, 4 and 6 months of age. Group A received three doses of DTaP-HB-IPV; Group B received DTaP-HB-IPV at 2 and 4 months and DTaP-HB wi th OPV (Orimune) at 6 months; Group C received three doses of DTaP-HB with licensed IPV (IPOL) administered separately; Group D received separate dose s of OPV, DTaP (Infanrix; GSK) and HB (Engerix; GSK). All subjects received conjugate Haemophilus influenzae type b vaccine (Hib) (OmniHIB) at 2, 4 an d 6 months of age given at a separate injection site. Subjects who returned at 12 to 18 months of age (229) received booster immunization with DTaP an d Hib. Safety was evaluated after each vaccine dose. Blood was drawn before the first dose and one month after the third dose as well as before and af ter the booster dose. Results. There were no vaccine-related serious adverse events in any group after any vaccine dose. Minor systemic and local adverse events were also n ot significantly different among the four groups after any dose. There were no differences in the immune response rates for Hib, HB, polio (types 1, 2 and 3), diphtheria, tetanus or pertussis antigens (pertussis toxin, filame ntous hemagglutinin, pertactin) among groups, although there were some quan titative differences in specific antibody titers among groups. DTaP-HB-IPV and DTaP-HB combination vaccines had safety and immunogenicity equivalent t o those of standard individually administered vaccines. The new IPV was not inferior to IPOL. Conclusion. Use of the pentavalent combination vaccine would greatly reduce the number of required injections during the first 2 years of life, thereb y simplifying the immunization schedule, enhancing compliance and facilitat ing acceptance of additional injections engendered by introduction of newer vaccines.