Immunogenicity and safety of an investigational quadrivalent meningococcal ACWY tetanus toxoid conjugate vaccine in healthy adolescents and young adults 10 to 25 years of age.

BACKGROUND

An investigational quadrivalent Neisseria meningitidis serogroups A, C, W-135, and Y tetanus toxoid conjugate vaccine (MenACWY-TT) has been developed to expand available options for vaccination against invasive meningococcal disease.

METHODS

A total of 784 healthy adolescents and young adults 11 to 25 years of age were randomized (3:1) to receive a single dose of the MenACWY-TT vaccine or a licensed MenACWY diphtheria toxoid conjugate vaccine (MenACWY-DT). An additional nonrandomized group of 88 subjects 10 years of age received the MenACWY-TT vaccine only (MenACWY-TT/10). Immunogenicity was assessed 1 month postvaccination by human complement serum bactericidal assay (hSBA) for all serogroups. Solicited local and general symptoms were recorded for 8 days postvaccination and safety outcomes for 6 months.

RESULTS

One month postvaccination, 81.9% to 96.1% of subjects had hSBA titers ≥ 1:8 in the MenACWY-TT group compared with 70.7% to 98.8% in the MenACWY-DT group. Exploratory analyses showed the proportion of subjects with hSBA titers ≥ 1:4 and ≥ 1:8 to be higher in the MenACWY-TT group than in the MenACWY-DT group for serogroups A, W-135, and Y. GMTs adjusted for age strata and baseline titer 1 month postvaccination were higher in the MenACWY-TT group than in the MenACWY-DT group for all 4 serogroups. The percentage of subjects reporting solicited local and general symptoms of any or Grade 3 severity or serious adverse events was similar between the 2 groups. Immune response and reactogenicity in the MenACWY-TT/10 group was similar to that in the MenACWY-TT group, except for higher hSBA-MenA GMTs in the MenACWY-TT/10 group.

CONCLUSIONS

The investigational MenACWY-TT vaccine was immunogenic in adolescents and young adults, with an acceptable safety profile.