A prior phase 3, randomised, multicenter trial demonstrated the immunogenicity of a primary immunisation with the quadrivalent meningococcal vaccine conjugated to tetanus toxoid (MenACWY-TT) or the quadrivalent meningococcal polysaccharide vaccine in individuals aged 11 to 17 years (MenACWY-PS). This research looked at the safety and immunogenicity of a MenACWY-TT booster given 10 years after receiving a main dose of either MenACWY-TT or MenACWY-PS. The primary immunogenicity objective was booster response, which was measured 1 month after the booster using serum bactericidal antibody tests with rabbit complement (rSBA). The percentage of individuals reporting local and general adverse events (AEs) 4 days following MenACWY-TT booster was one of the safety objectives. The booster phase was completed by 169 and 58 participants in the MenACWY-TT and MenACWY-PS groups, respectively, out of a total of 229 subjects enrolled. MenACWY-TT and MenACWY-PS receivers exhibited similar rates of booster responses to serogroups A, W, and Y, but more MenACWY-TT recipients than MenACWY-PS recipients had a booster response to serogroup C.

The MenACWY-TT and MenACWY-PS boosters elicited rSBA titers 1:8 in 100 percent and 98.0 percent of participants across all serogroups, respectively; 100 percent and 96.1 percent of all subjects had titers 1:128. In conclusion, a MenACWY-TT booster dosage given following either a MenACWY-TT or MenACWY-PS main dose evoked powerful immunological responses and was well tolerated. After initial MenACWY-TT vaccination, functional antibody responses can continue up to ten years.

Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2020.1744363

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