Both after 1 dose and after 2 doses, the MMRV vaccine was at least as immunogenic as concomitant MMR and varicella vaccination suggesting that it could be suitable for use according to current vaccination schedules.

Coadministration of the DTPa-HBV-IPV/Hib and 7vPn vaccines at separate injection sites during the same vaccination visit was effective and safe.

The combined hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio Haemophilus influenzae type b (DTPa-HBV-IPV/Hib) vaccine produces similar hepatitis B responses as the HBV monovalent vaccine. Booster vaccination of immunocompetent individuals primed against hepatitis B in infancy is currently not recommended. We investigated persisting immunity to hepatitis B in 4-6 (Study A; 106745) and 7-9 (Study B; 106744) year-old children primed in infancy and boosted in the second year of life with DTPa-HBV-IPV/Hib. Immunity was assessed by measuring persisting anti-HBs antibodies and evaluating the response to a challenge dose of HBV vaccine. At 4-6 years of age 86.0% of 186 subjects had persisting anti-HBs > or =10 mIU/ml increasing to 98.4% after the challenge. At 7-9 years of age, 78.0% of 186 subjects continued to have anti-HBs antibody concentrations > or =10 mIU/ml, increasing to 98.9% after the challenge. In both studies anti-HBs antibody GMC rose >80-fold. An anamnestic response to the HBV challenge was observed in 95.7% and 98.9% of subjects in Studies A and B, respectively. In both studies, 87% of 38 subjects with initially undetectable circulating anti-HBs antibodies (>3.3 IU/ml) achieved the 10 mIU/ml threshold after challenge; > or =97.0% of subjects with detectable antibodies before the challenge at least quadrupled their concentration. Post-vaccination anti-HBs concentrations were directly related to persisting antibody concentrations and the concentrations achieved after the booster dose in the second year of life. The HBV vaccine challenge dose was well tolerated. These studies show that primary and booster vaccination with combined DTPa-HBV-IPV/Hib (Infanrix hexa) induces sustained immune memory against hepatitis B up to age 9 years.

Reduced-antigen-content pertussis vaccines designed initially for booster vaccination of adolescents and adults can also be used to vaccinate pre-school age children. Combination vaccines, which reduce the number of administered injections, combine multiple antigens including inactivated poliovirus (IPV), which is recommended in this age group in some countries. This randomised, controlled study compared a combined diphtheria-tetanus-acellular pertussis-inactivated polio-containing booster vaccine, dTpa-IPV (Boostrix Polio, n=822), to separately administered dTpa (Boostrix) and IPV (IPV Mérieux, n=136) in 4-8-year-old children who had previously received four doses of DTPa. Additional serological assessment was performed 1 year after the booster dose. One month after vaccination, seroprotection/vaccine response rates were similar for both groups. At least 99.9% of the subjects had protective antibodies against diphtheria, tetanus and polio, and at least 90.1% had a vaccine response to pertussis antigens after dTpa-IPV. Reactogenicity of dTpa-IPV was comparable to dTpa + IPV. Fever and grade 3 loss of appetite occurred more commonly after dTpa-IPV, whereas swelling and grade 3 pain occurred more frequently after separately administered dTpa + IPV (P<0.05 for all). However, 95% CIs overlapped in all cases. Large swelling reactions after dTpa-IPV occurred less commonly than have been reported after a fifth dose of DTPa. One year after the booster, 98.6% of the subjects tested continued to have protective antibodies against diphtheria, tetanus and polio, and at least 81.2% were seropositive for pertussis components. The reduced-antigen-content dTpa-IPV vaccine was immunogenic, well tolerated and safe in pre-school age children. It provides immunity against four diseases in a single injection, with the potential reactogenicity benefit of a reduced-antigen dose.