Meningococcal quadrivalent ACYW-TT conjugated vaccine at 6–23 months: phase III study (US/Puerto Rico)

When administered as a two-dose series (1 + 1 schedule), MenACYW-TT demonstrated comparable/higher immunogenicity to MenACWY-CRM (ages 6-7 and 12-13 months) and the safety profiles of these quadrivalent meningococcal vaccines were similar. MenACYW-TT was non-inferior to MenACWY-CRM in terms of seroresponse rates and proportion of participants with antibody titer ≥1:8 after a second dose at age 12-13 months. This phase III study is the first to confirm the safety and immunogenicity of MenACYW-TT in infants and supports its use as a two-dose series from 6 months of age.