Immunogenicity and Reactogenicity of a Reduced Schedule of a 4-component Capsular Group B Meningococcal Vaccine: A Randomized Controlled Trial in Infants

Abstract

The four-component capsular group B meningococcal vaccine (4CMenB) was licensed as a four-dose infant schedule but introduced into the UK as three doses at two, four and 12 months of age. We describe the immunogenicity and reactogenicity of the 2+1 schedule in infants. Infants were randomised to receive 4CMenB with routine immunisations (test group) at two, four and 12 months or 4CMenB alone at six, eight and 13 months of age (control group). Serum bactericidal antibody (SBA) assay against a serogroup B meningococcal reference strain (44/76-SL), memory B cell responses to fHbp, NadA, NHBA and PorA and reactogenicity was measured. 187 infants were randomised (test group:94; control group:93). In the test group 4CMenB induced SBA titres above the putative protective threshold (1:4) after primary and booster doses in 97% of participants. Post-booster, the SBA GMT (72.1; 95%CI 51.7–100.4) was numerically higher than the SBA GMT determined post-primary vaccination (48.6; 95%CI 37.2–63.4).After primary immunisations, memory B cells responses did not change when compared with baseline controls, but frequencies significantly increased after booster.Higher frequency of local and systemic adverse reactions was associated to 4CMenB. A reduced schedule of 4CMenB was immunogenic and established immunological memory after booster.