Background: This study evaluated the immunogenicity, reactogenicity and safety of the combined Haemophilus influenzae type B Neisseria meningitidis serogroup C tetanus toxoid conjugate vaccine (Hib-MenC-TT) coadministered with diphtheria, tetanus, acellular pertussis hepatitis B–inactivated poliovirus (DTPa-HBV-IPV) as 2 primary and 1 booster doses at 3, 5 and 11 months of age.
Methods: In this phase III open study (NCT00327184), 709 infants were randomized in 2 parallel groups (1:1) to receive either Hib-MenC-TT coadministered with DTPa-HBV-IPV or control vaccines (MenC-TT coadministered with DTPa-HBV-IPV/Hib). Serum bactericidal activity for MenC (rSBA-MenC) and antibody concentrations against polyribosylribitol phosphate from Hib (anti-PRP) and hepatitis B (anti-HBs) were measured at 1 month after dose 2, before booster and 1 month after booster dose. Solicited (local/general) and unsolicited symptoms were assessed up to 4 and 31 days, respectively, after each vaccination. Serious adverse events were recorded throughout the study.
Results: One month after dose 2, high percentages of infants in both groups had rSBA-MenC titers ≥8 (≥99.1%), anti-PRP concentrations ≥0.15 μg/mL (≥96.5%) and anti-HBs concentrations ≥10 mIU/mL (≥95.3%), which persisted up to the booster vaccination (≥94.5%, ≥86.1%, ≥94.2%) and increased again after the booster dose (100%, 100%, ≥99%). Exploratory analyses indicated that rSBA-MenC geometric mean titers were lower and anti-PRP geometric mean concentrations were higher in the infants vaccinated with Hib-MenC-TT compared with the control vaccines at all time points. The safety profiles of the coadministered vaccines were similar in both groups.
Conclusions: The Hib-MenC-TT and DTPa-HBV-IPV vaccines are immunogenic with a clinically acceptable safety profile when coadministered as 2 primary doses during infancy and 1 booster dose at 11 months of age.