Immunogenicity and reactogenicity of primary immunization with a hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio-Haemophilus influenzae type B vaccine coadministered with two doses of a meningococcal C-tetanus toxoid conjugate vaccine.

Background: This study evaluated the concurrent use of meningococcal C tetanus conjugate (MenC-TT) vaccine (NeisVac-C) with DTaP-based combinations, according to 2 vaccination schedules, one of which included hepatitis B vaccination at birth (Trial DTaP-HBV-IPV/Hib-097). Methods: Healthy infants were randomized to receive either DTaP-HBV-IPV/Hib (Infanrix hexa) at 2, 4, and 6 months (N = 115) or HBV at birth followed by DTaP-HBV-IPV/Hib at 2 and 6 months and DTaP-IPV/Hib (Infanrix-IPV Hib) at 4 months (N = 115). In both groups 2 doses of MenC-TT conjugate were coadministered at 2 and 4 months, and compared with 3 doses of MenC-CRM 197 conjugate (Meningitec) coadministered at 2, 4, and 6 months with DTaP-HBV-IPV/Hib (N = 120). Antibody concentrations were measured at 2, 6 and 7 months. Solicited local and general symptoms, unsolicited symptoms, and serious adverse events (SAEs) were recorded. Results: All MenC-TT recipients had seroprotective concentrations of anti-PRP antibodies (≥0.15 μg/mL) 1 month after the third vaccine dose and all had SBA-MenC titers ≥1:8 after the second dose of MenC-TT. These responses were noninferior to those seen after 3 doses of DTaP-HBV-IPV/Hib and MenC-CRM. Anti-PRP antibody GMCs were significantly higher in MenC-TT than MenC-CRM vaccinees (7.9, 7.3, 3.8 μg/mL, respectively). Immune responses to all other coadministered antigens were unimpaired, with seroprotection/seropositivity rates ≥98.1% in MenC-TT vaccinees. All schedules studied were well tolerated, with no differences in reactogenicity between the study groups. Conclusions: Coadministration of DTaP-HBV-IPV/Hib or DTaP-IPV/Hib with 2 doses of MenC-TT conjugate vaccine is safe, well tolerated, and immunogenic, with no impairment of the response to the coadministered antigens.