2725. Immunogenicity and Safety of a Booster Dose of a Quadrivalent Meningococcal Conjugate Vaccine (MenACYW-TT) in Adolescents and Adults

Abstract

Background: The MenACYW‐TT conjugate vaccine is a quadrivalent meningococcal vaccine that contains tetanus toxoid as carrier protein. Vaccine is intended for global use in all age groups (i.e., individuals 6 weeks of age and older). This Phase III study evaluated the safety and immunogenicity of the vaccine when compared with a licensed quadrivalent meningococcal conjugate vaccine in individuals ≥ 15 years of age. Methods: A randomized, modified double‐blind study (NCT02752906) was conducted in the United States and Puerto Rico. The study evaluated 810 participants primed with a licensed quadrivalent meningococcal conjugate vaccine (Menactra® [MenACWY‐D] or MENVEO® [MenACWY‐CRM]) in the 4 to 10 years prior to enrollment. Participants were randomly assigned to receive either a single booster dose of MenACYW‐TT conjugate vaccine or MenACWY‐D. Safety data were collected up to 6 months post‐vaccination. Results: Non‐inferiority of immune response was demonstrated for MenACYW‐TT vs. MenACWY‐D based on percentages of participants achieving an serum bactericidal assay with human complement (hSBA) seroresponse for serogroups A, C, W, and Y at Day 30 post‐vaccination. Post‐vaccination hSBA geometric mean titers (GMTs) were higher following administration of MenACYW‐TT compared with MenACWY‐D for age subgroups ≥15 to < 18 years and ≥18 years. Relative to MenACWY‐D, post‐vaccination hSBA GMTs were higher for all 4 serogroups following administration of MenACYW‐TT in participants who received the priming vaccine < 7 years prior to the booster; for participants who received priming vaccine ≥7 years prior to booster, post‐vaccination GMTs were higher for serogroups C, W and Y, and comparable for serogroup A. In MenACWY‐CRM‐primed subjects, hSBA vaccine seroresponse rates were comparable for all 4 serogroups regardless of the booster vaccine administered. In MenACWY‐D‐primed subjects, hSBA seroresponse rates following MenACYW‐TT booster administration were comparable for serogroups A and Y, and higher for serogroups C and W. Reactogenicity profiles were comparable across study groups. Conclusion: MenACYW‐TT conjugate vaccine was immunogenic and well tolerated when administered as a booster dose to individuals ≥15 years of age.