This phase 3B, open-label extension study (NCT01962207) compared the long-term persistence of antibodies induced by the quadrivalent meningococcal vaccine conjugated to tetanus toxoid (MenACWY-TT) to the meningococcal serogroup C vaccine conjugated to CRM (MenC-CRM) and the quadrivalent meningococcal polysaccharide vaccine (MenACWY Serum bactericidal antibody tests utilising rabbit (rSBA) or human (hSBA) complement were used to evaluate antibody responses against meningococcal serogroups A, C, W, and Y. At Year 10, the following percentages of participants had rSBA titers 1:8 for serogroups A, C, W, and Y: MenACWY-TT (toddlers), 65.6 percent, 82.8 percent, 31.3 percent, and 43.8 percent; MenC-CRM, 88.2 percent for serogroup C; MenACWY-TT (children), 88.9 percent, 84.1 percent, 67.1 percent, 65.9 percent; and MenACWY-PS, 28.6 percent, 81.0 percent, 23.8 percent, and 23.8 percent. For hSBA titers; MenACWY-TT (toddlers), 31.1 percent, 91.9 percent, 44.4 percent, 41.4 percent; MenC-CRM, 93.8 percent for serogroup C; MenACWY-TT (children), 34.8 percent, 91.1 percent, 61.2 percent, 72.6 percent; and MenACWY-PS, 33.3 percent, 100.0 percent, 26.3 percent, and 44.4 percent.
The percentage of individuals with vaccination response ranged from 75.7 percent to 100.0 percent one month following the MenACWY-TT booster across serogroups in all research groups. MenACWY-TT immunisation induced antibody responses that lasted 10 years. The MenACWY-TT booster dosage was well tolerated and produced strong immune responses.
Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2020.1746110
