Safety and immunogenicity of a quadrivalent meningococcal conjugate vaccine (MenACYW-DT): a multicenter, open-label, non-randomized, phase III clinical trial.

OBJECTIVE To assess the safety and immunogenicity of a quadrivalent meningococcal (groups A,C,Y,W) polysaccharide diphtheria toxoid conjugate vaccine (MenACYW-DT) in India. DESIGN Open-label, descriptive, non-randomized study. SETTING Three medical college hospitals, one each in New Delhi, Bengaluru and Mumbai, India. PARTICIPANTS 300 healthy, vaccine-naïve participants (100 children aged 2-11 years, 100 adolescents aged 12-17 years, and 100 adults aged 18-55 years). INTERVENTION One dose (0.5 mL) of MenACYW-DT administered intramuscularly. MAIN OUTCOME MEASURES Serum bactericidal antibody titers against A, C, Y, and W were measured before and after MenACWY-DT vaccination. Safety data were also collected. RESULTS Thirty days post-vaccination, geometric mean titers rose across all serogroups. Most participants had protective titers >8 (1/dil) across the four serogroups. The percentage (95% CI) achieving >8 (1/dil) in the Adolescent Group was typical - A: 96.9% (91.2%; 99.4%); C: 96.9% (91.2%; 99.4%); Y:100% (96.3%; 100%); W:100% (96.3%; 100%). In general, solicited reactions were mild and short-lived. Unsolicited events were uncommon and unrelated to vaccination. CONCLUSIONS MenACYW-DT was well tolerated and elicited a robust and protective immune response 30 days post-vaccination against meningococcal serogroups A, C, Y, and W-135 in the Indian study participants aged 2-55 years.