Quadrivalent meningococcal (MenACWY-TT) conjugate vaccine or a fourth dose of H. influenzae–N. meningitidis C/Y conjugate vaccine (HibMenCY-TT) is immunogenic in toddlers who previously received three doses of HibMenCY-TT in infancy

Abstract

BackgroundImmunogenicity and safety of a single dose of MenACWY-TT or a fourth dose of HibMenCY-TT were evaluated in the second year of life in HibMenCY-TT-primed toddlers. MethodsHealthy infants were randomized (5:1) and primed at 2, 4 and 6 months of age with HibMenCY-TT and diphtheria–tetanus–acellular pertussis–hepatitis B-inactivated poliovirus (DTaP–HBV–IPV) vaccine; or Hib-TT and DTaP–HBV–IPV (control). Recipients of HibMenCY-TT+DTaP–HBV–IPV were re-randomized (2:2:1) to receive MenACWY-TT at 12–15 months and DTaP at 15–18 months; MenACWY-TT co-administered with DTaP at 15–18 months; or HibMenCY-TT at 12–15 months and DTaP at 15–18 months. Controls received DTaP only at 15–18 months due to Hib conjugate vaccine shortage. Serum bactericidal activity using human complement (hSBA) and safety were assessed one month after meningococcal vaccination. ResultsAfter vaccination with MenACWY-TT at 12–15 months or MenACWY-TT+DTaP at 15–18 months, all subjects previously primed for serogroups C/Y had hSBA ≥1:8 for these serogroups. At least 96.1% also had hSBA ≥1:8 for serogroups A/W. All subjects in the HibMenCY-TT group had hSBA ≥1:8 for serogroups C/Y. All pre-defined statistical criteria for meningococcal immunogenicity were satisfied. All vaccination regimens had acceptable safety profiles. ConclusionChildren primed with three doses of HibMenCY-TT who then received a single dose of MenACWY-TT or a fourth dose of HibMenCY-TT had robust increases in hSBA titers for serogroups C/Y. These data provide support that MenACWY-TT, given with or without the fourth scheduled dose of DTaP could be administered as an alternative to a fourth dose of HibMenCY-TT in the second year of life.This study (110870/110871) is registered at www.clinicaltrials.govNCT00614614.