Immunogenicity and safety of MenACWY-TT, a meningococcal conjugate vaccine, co-administered with routine childhood vaccine in healthy infants: A phase III, randomized study.

BACKGROUND

Invasive meningococcal disease has a high burden in young children, particularly during infancy. We investigated the immunogenicity and safety of a quadrivalent meningococcal conjugated vaccine (MenACWY-TT) co-administered with routine vaccines in healthy infants.

METHODS

In this phase IIIb study (NCT01340898) conducted in 2 centers in Lebanon and Mexico, 750 infants were randomized (2:1:1) to receive MenACWY-TT according to 3 schedules: 3+1 (at ages 2, 4, 6 and 15-18 months; group ACWY3+1); 1+1 (at 6 and 15-18 months; group ACWY1+1) or single-dose at 15-18 months (group ACWY1). All infants received PHiD-CV and DTPa-IPV/Hib at ages 2, 4, 6, 15-18 months. Immune responses to MenACWY-TT were assessed by rSBA and hSBA at 7 months (groups ACWY3+1, ACWY1+1) and pre- and post-vaccination at 15-18 months of age (all groups). Immune responses to co-administered vaccines, reactogenicity and safety were also evaluated.

RESULTS

Immunogenicity of MenACWY-TT at 1 month post-primary vaccination was demonstrated in group ACWY3+1: the lower limit of the 95% confidence interval for the percentage of infants with rSBA titers ≥8 was >80% for each serogroup. At 7 months of age, ≥93.9% of MenACWY-TT-primed infants had rSBA titers ≥8. Post-MenACWY-TT vaccination at age 15-18 months, ≥96.3% of participants in all groups had rSBA titers ≥8, regardless of the number of doses received previously. The percentage of infants with hSBA titers ≥4 were ≥87.2% and ≥89.7% at post-primary and booster/single-dose vaccination, respectively. Immune responses to PHiD-CV and DTPa-IPV/Hib did not seem impacted by co-administration with MenACWY-TT in infancy. The incidence of all adverse events was similar among groups. Serious adverse events were reported for 63/750 children in all groups; none were considered vaccine-related by investigators.

CONCLUSION

Primary vaccination with 3 or 1 dose(s) of MenACWY-TT when co-administered with routine pediatric vaccines in infants is immunogenic and well-tolerated.