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  • A novel meningococcal outer...
    Marsay, L; Dold, C; Green, C.A; Rollier, C.S; Norheim, G; Sadarangani, M; Shanyinde, M; Brehony, C; Thompson, A.J; Sanders, H; Chan, H; Haworth, K; Derrick, J.P; Feavers, I.M; Maiden, M.C; Pollard, A.J

    The Journal of infection, 09/2015, Letnik: 71, Številka: 3
    Journal Article

    Summary Objectives Outer membrane vesicle (OMV) vaccines are used against outbreaks of capsular group B Neisseria meningitidis (MenB) caused by strains expressing particular PorA outer membrane proteins (OMPs). Ferric enterobactin receptor (FetA) is another variable OMP that induces type-specific bactericidal antibodies, and the combination of judiciously chosen PorA and FetA variants in vaccine formulations is a potential approach to broaden protection of such vaccines. Methods The OMV vaccine MenPF-1 was generated by genetically modifying N. meningitidis strain 44/76 to constitutively express FetA. Three doses of 25 μg or 50 μg of MenPF-1 were delivered intra-muscularly to 52 healthy adults. Results MenPF-1 was safe and well tolerated. Immunogenicity was measured by serum bactericidal assay (SBA) against wild-type and isogenic mutant strains. After 3 doses, the proportion of volunteers with SBA titres ≥1:4 (the putative protective titre) was 98% for the wild-type strain, and 77% for the strain 44/76 FetA on PorA off compared to 51% in the strain 44/76 FetA off PorA off , demonstrating that vaccination with MenPF-1 simultaneously induced FetA and PorA bactericidal antibodies. Conclusion This study provides a proof-of-concept for generating bactericidal antibodies against FetA after OMV vaccination in humans. Prevalence-based choice of PorA and FetA types can be used to formulate a vaccine for broad protection against MenB disease.