Safety and immunogenicity of a primary course and booster dose of a combined diphtheria, tetanus, acellular pertussis, hepatitis B and inactivated poliovirus vaccine.

Primary immunization at 3, 4.5, and 6 months and boosting between 15 and 27 months of age with combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus (DTPa-HBV-IPV) vaccine was compared with separate administration of DTPa-HBV and IPV to healthy children (trials DTPa-HBV-IPV-019/033). Antibody titres were measured before and 1 month after primary and booster courses. Solicited local and general symptoms were recorded using diary cards. One month after primary vaccination, all children in both groups developed antibody titres above the assay cut-off for all vaccine components. Significantly higher anti-diphtheria, anti-pertactin (PRN) and anti-polio GMTs were measured following DTPa-HBV-IPV than DTPa-HBV plus IPV. Prior to boosting similar seroprotection/seropositivity rates were recorded in both groups. After boosting all children had seroprotective levels of diphtheria, tetanus, polio and HBV. Criteria for pertussis vaccine response were fulfilled in most children. Significantly higher anti-PRN GMTs were measured following DTPa-HBV-IPV than DTPa-HBV plus IPV. There was no difference between groups in the incidence or intensity of local and general symptoms after primary or booster vaccination, except for fever which was more frequent after the booster dose in the combined vaccine group. Both vaccine regimens were well tolerated and immunogenic, however the combined administration has the advantage of being administered as a single injection.