Immunogenicity and safety of a quadrivalent meningococcal conjugate vaccine administered concomitantly with measles, mumps, rubella, varicella vaccine in healthy toddlers.

Abstract Background Invasive meningococcal disease can have devastating outcomes, especially in high-risk groups such as infants. As infants are recommended to receive multiple vaccines during a single office visit, this phase 3 study assessed the safety and immune response to MenACWY-CRM at alternative visits in older infants and concomitant use with measles, mumps, rubella, varicella vaccine (MMRV) at 12 months of age. Methods Two age groups were concurrently enrolled: 7- to 9-month-old infants who received 2 doses of MenACWY-CRM at 7–9 and 12 months and were randomized 1:1 to receive MenACWY-CRM with or without MMRV at 12 months, and 12-month-old infants who received MMRV only at12 months. Using predefined non-inferiority criteria, immune responses to the antigens in MMRV were compared between those who did and did not receive MenACWY-CRM; immune responses to MenACWY-CRM as measured by the percentage of subjects with human serum bactericidal activity (hSBA) titers ≥ 8, were compared between those who did and did not receive concomitant MMRV. Adequacy of the immune response to 2 doses of MenACWY-CRM administered at 7–9 and 12 months was also assessed. Local and systemic reactions, adverse events resulting in withdrawal or requiring medical attention and serious adverse events were monitored. Results Concomitant administration of MMRV with MenACWY-CRM did not affect the immune response to either vaccine. The 2-dose series of MenACWY-CRM induced adequate immune response to all 4 serogroups. No increased reactogenicity was observed with MenACWY-CRM + MMRV compared with MMRV alone, and there were no study-related serious adverse events. Conclusions Concomitant administration of MenACWY-CRM with MMRV vaccinations at 12 months was well-tolerated, without safety concerns. Robust immune responses to all components of both vaccines were produced and all criteria for non-inferiority were met, supporting the use of a 2-dose regimen of MenACWY-CRM in this age group.