1. A large portion of meningococcal antigen typing system-negative meningococcal strains from spain is killed by sera from adolescents and infants immunized with 4CMenB.
- Author
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Abad R, Biolchi A, Moschioni M, Giuliani MM, Pizza M, and Vázquez JA
- Subjects
- Adolescent, Antigens, Bacterial analysis, Antigens, Bacterial genetics, Antigens, Bacterial immunology, Enzyme-Linked Immunosorbent Assay, Genotype, Genotyping Techniques, Humans, Infant, Meningococcal Infections immunology, Meningococcal Vaccines administration & dosage, Neisseria meningitidis classification, Neisseria meningitidis physiology, Phenotype, Porins analysis, Porins genetics, Porins immunology, Spain, Bacterial Typing Techniques, Blood Bactericidal Activity, Meningococcal Infections prevention & control, Meningococcal Vaccines immunology, Microbial Viability, Neisseria meningitidis immunology, Vaccination methods
- Abstract
A new vaccine (the 4CMenB 4-component protein vaccine [Bexsero], which includes PorA, factor H-binding protein [fHbp], neisserial heparin-binding antigen [NHBA], and Neisseria adhesin A [NadA]) against serogroup B meningococci has recently been approved for use in people older than age 2 months in Europe, Australia, and Canada. Preapproval clinical efficacy studies are not feasible for invasive meningococcal disease because its incidence is low/very low, and the serum bactericidal antibody (SBA) titer (or the human SBA [hSBA] titer when human complement is used in the assay) has been used as a surrogate marker of protection. However, the hSBA assay cannot be used on a large scale, and therefore, a meningococcal antigen typing system (MATS) was developed. MATS combines conventional PorA genotyping with an enzyme-linked immunosorbent assay (ELISA) that quantifies both the expression and the cross-reactivity of antigenic variants. The assay has been used to evaluate the potential of the 4CMenB meningococcal group B vaccine to cover group B strains in several countries. Some recent data suggest that MATS is a conservative predictor of strain coverage. We used pooled sera from adolescents and infants to test by the hSBA assay 10 meningococcal group B strains isolated in Spain that were negative for the 3 antigens (n = 9) or that had very low levels of the 3 antigens (n = 1) by MATS. We found that all strains were killed by sera from adolescents and that 5 of the 10 strains were also killed, although at a low titer, by sera from infants. Our data confirm that MATS underestimates vaccine coverage., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)
- Published
- 2015
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