Immunogenicity and Safety of a Two-Dose Series of a Meningococcal (Groups A, C, W, and Y) Polysaccharide Diphtheria Toxoid Conjugate Vaccine (Men-ACWY-D) in Healthy Japanese Adults

The quadrivalent meningococcal polysaccharide diphtheria toxoid conjugate vaccine (Men-ACWY-D) has been licensed for use in Japan since 2014. An earlier registration study demonstrated the immunogenicity of a single dose Japanese adults, wherein against serogroup C was lowest. determination potential to increase response with second was, therefore, interest. This (NCT02591290) evaluated safety and two doses administered 8 weeks apart 60 healthy adults aged 20–55 years. Blood samples were collected at 28–35 days after vaccination. Immunogenicity endpoints included seroprotection seroconversion rates. Safety assessments systemic adverse events (AEs), non-serious AEs, serious AEs. Fifty-eight participants (96.7%) completed study. rates serogroups A, C, W, Y before vaccination 76.8%, 26.8%, 50.0%, respectively, increasing 100%, 83.9%, 91.1%, 96.4% 92.9%, 94.6%, doses. four 93.8%, 97.1%, 94.1%, first dose, 96.9%, second. between insignificant, there no concerns. two-dose series well tolerated; however, clinical benefits within seemed be low.