Immunogenicity, Reactogenicity, and Safety of a Pentavalent Meningococcal ABCWY Vaccine in Adolescents and Young Adults Who Had Previously Received a Meningococcal ACWY Vaccine: A Phase 3, Randomized Controlled Clinical Study.

Abstract

A MenABCWY vaccine containing 4CMenB and MenACWY-CRM vaccine components has been developed to protect against the 5 meningococcal serogroups that cause most invasive disease cases. In this phase 3 study, healthy participants aged 15-25 years, who had received MenACWY vaccination ≥4 years previously, were randomized (1:1) to receive 2 MenABCWY doses 6 months apart or 1 MenACWY-CRM dose. Primary objectives were to demonstrate the noninferiority of MenABCWY 1 month postvaccination versus MenACWY-CRM, with a lower limit of 2-sided 95% confidence interval above -10% for group differences in 4-fold rise in human serum bactericidal antibody (hSBA) titers against serogroups ACWY, and to evaluate reactogenicity and safety. Secondary endpoints included percentages of participants with hSBA titers greater than or equal to the lower limit of quantitation (≥LLOQ) against serogroups ACWY and vaccine antigen-specific serogroup B (MenB) indicator strains. Noninferiority of MenABCWY versus MenACWY-CRM was demonstrated following each MenABCWY dose. Percentages of participants with hSBA titers ≥LLOQ for serogroups ACWY were 97.9%-98.9% and 99.5%-100% following 1 and 2 MenABCWY doses, respectively, and 96.8%-99.0% following 1 MenACWY-CRM dose. After 2 MenABCWY doses, 75.6%-96.3% of participants had hSBA titers ≥LLOQ against MenB indicator strains. The MenABCWY vaccine was well tolerated in MenACWY-primed individuals, with a favorable safety profile. Immune responses against serogroups ACWY following 1 and 2 doses of investigational MenABCWY vaccine are noninferior to those following MenACWY-CRM in MenACWY-primed adolescents and young adults. Robust immune responses were observed against MenB indicator strains after 2 MenABCWY doses administered 6 months apart. Clinical Trials Registration. NCT04707391.