Immunogenicity and tolerability of a multicomponent meningococcal serogroup B (4CMenB) vaccine in healthy adolescents in Chile: a phase 2b/3 randomised, observer-blind, placebo-controlled study
ABSTRACT Effective glycoconjugate vaccines against Neisseria meningitidis serogroups A, C, W-135, and Y have been developed, but serogroup B remains a major cause of severe invasive disease in infants and adolescents worldwide. We assessed immunogenicity and tolerability of a four-component vaccine (4CMenB) in adolescents.
We did a randomised, observer-blind, placebo-controlled, study at 12 sites in Santiago and Valparaíso, Chile. Adolescents aged 11-17 years received one, two, or three doses of 4CMenB at 1 month, 2 month, or 6 month intervals. Immunogenicity was assessed as serum bactericidal activity using human complement (hSBA) against three reference strains for individual vaccine antigens, and assessed by ELISA against the fourth strain. Local and systemic reactions were recorded 7 days after each vaccination, and adverse events were monitored throughout the study. Participants were initially randomised to five groups (3:3:3:3:1) during the primary phase to receive either one dose, two doses 1 or 2 months apart, or three doses of 4CMenB, or three doses of placebo, with an additional three groups generated for the booster phase. All subjects received at least one dose of 4CMenB. Geometric mean titres, proportions of participants with serum bactericidal antibody titres of 4 or more, and Clopper-Pearson 95% CIs were calculated. The study is registered with ClinicalTrials.gov, number NCT00661713.
Overall, 1631 adolescents (mean age 13·8 [SD 1·9] years) received at least one dose of 4CMenB. After two or three doses, 99-100% of recipients had hSBA titres of 4 or more against test strains, compared with 92-97% after one dose (p<0·0145) and 29-50% after placebo. At 6 months 91-100% of participants still had titres of 4 or more for each strain after two or three doses, but only 73-76% after one dose; seroresponse rates reached 99-100% for each strain after second or third doses at 6 months. Local and systemic reaction rates were similar after each 4CMenB injection and did not increase with subsequent doses, but remained higher than placebo. No vaccine-related serious adverse events were reported and no significant safety signals were identified.
On the basis of immunogenicity responses this study provides evidence for an adolescent 4CMenB vaccine schedule of two doses, 1-6 months apart, to provide protection against meningococcal B infection. The extent of this protection against meningococcus B variants circulating worldwide will be determined by national surveys.
Novartis Vaccines and Diagnostics.
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ABSTRACT: 4CMenB (Bexsero), a vaccine developed against invasive meningococcal disease caused by capsular group B strains (MenB), was recently licensed for use by the European Medicines Agency. Assessment of 4CMenB strain coverage in specific epidemiologic settings is of primary importance to predict vaccination impact on the burden of disease. The Meningococcal Antigen Typing System (MATS) was developed to predict 4CMenB strain coverage, using serum bactericidal antibody assay with human complement (hSBA) data from a diverse panel of strains not representative of any specific epidemiology. To experimentally validate the accuracy of MATS-based predictions against strains representative of a specific epidemiologic setting. We used a stratified sampling method to identify a representative sample from all MenB disease isolates collected from England and Wales in 2007-2008, tested the strains in the hSBA assay with pooled sera from infant and adolescent vaccinees, and compared these results with MATS. MATS predictions and hSBA results were significantly associated (P=0.022). MATS predicted coverage of 70% (95% CI, 55-85%) was largely confirmed by 88% killing in the hSBA (95% CI, 72-95%). MATS had 78% accuracy and 96% positive predictive value against hSBA. MATS is a conservative predictor of strain coverage by the 4CMenB vaccine in infants and adolescents.Vaccine 08/2013; 31(43). DOI:10.1016/j.vaccine.2013.08.006 · 3.49 Impact Factor
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ABSTRACT: Novel serogroup B meningococcal vaccines are currently in late stage development and may be used in mass immunisation campaigns over the coming years. This represents an exciting development in the prevention of childhood meningitis, however monitoring the impact of these vaccines on meningococcal disease epidemiology will provide significant challenges. Although designed to prevent serogroup B meningococcal disease the vaccine antigens are not serogroup specific, creating the potential for multiple definitions of vaccine effectiveness and vaccine failure.Vaccine 01/2012; 30 Suppl 2:B67-72. DOI:10.1016/j.vaccine.2011.12.126 · 3.49 Impact Factor
Article: Recombinant bacterial vaccines[Show abstract] [Hide abstract]
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