Background: The immunogenicity and safety of the investigational diphtheria, tetanus, acellular pertussis, hepatitis B, poliomyelitis, Haemophilus influenzae type b (Hib) and meningococcal serogroup C (MenC) heptavalent combination vaccine were compared with those of licensed control vaccines.
Methods: In this open, phase II, randomized study (NCT01090453), 480 infants from Germany, France and Canada received the heptavalent vaccine (Hepta group) or hexavalent and monovalent MenC control vaccines (HexaMenC group) co-administered with a 13-valent pneumococcal conjugate vaccine at 2, 4 and 12 months of age. Immunogenicity was measured 1 month after the second primary dose, and before and 1 month after the booster dose. Safety and reactogenicity were also evaluated.
Results: Non-inferiority of immune responses to MenC and Hib induced by 2-dose primary vaccination with the heptavalent vaccine versus control vaccines was demonstrated. In exploratory analyses, postprimary and postbooster functional antibody geometric mean titers against MenC tended to be lower (1119.5 vs. 3200.5; 2653.8 vs. 6028.4) and antibody geometric mean concentrations against Hib higher (1.594 vs. 0.671 μg/mL; 17.678 vs. 13.737 μg/mL) in the Hepta versus the HexaMenC group. The heptavalent and control vaccines were immunogenic to all other antigens, although immune responses to poliovirus were lower than expected in both groups. No differences in safety and reactogenicity profiles were detected between groups.
Conclusions: The heptavalent vaccine induced non-inferior MenC and Hib responses compared with control vaccines. Both vaccination regimens, when administered at 2, 4 and 12 months of age, had comparable safety profiles and were immunogenic to all antigens, with lower-than-expected responses to poliomyelitis.