title: Validation of a routine opsonophagocytosis assay to predict invasive pneumococcal disease efficacy of conjugate vaccine in children.
abstract: Immunological evaluation of the clinical impact of vaccines designed to protect against infection by Streptococcus pneumoniae requires measurement of serotype-specific functional antibodies. We describe the development and validation of a viable pneumococcal opsonophagocytosis assay (OPA) that can be used for routine serological analysis of paediatric immune responses after immunization. OPA seropositivity (%> or =8 threshold) reflected well invasive pneumococcal disease (IPD) effectiveness. In contrast, the 22F inhibition ELISA seropositivity (%> or =0.20microg/ml threshold) overestimated (19F) or underestimated (6B, 23F, 6A) IPD effectiveness for several serotypes. The seropositivity as estimated by a standardized and highly reproducible OPA was predictive for the serotype-specific IPD efficacy of pneumococcal conjugate vaccines.
authors.affiliation: GlaxoSmithKline Biologicals, Rue de l'Institut 89, 1330 Rixensart, Belgium. isabelle.henckaerts@gskbio.com
authors.forename: Isabelle
authors.initials: I
authors.lastname: Henckaerts
authors.forename: Nathalie
authors.initials: N
authors.lastname: Durant
authors.forename: Dany
authors.initials: D
authors.lastname: De Grave
authors.forename: Lode
authors.initials: L
authors.lastname: Schuerman
authors.forename: Jan
authors.initials: J
authors.lastname: Poolman
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018922:HL-60 Cells; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D022401:Meningococcal Vaccines / Q000276:immunology* / Q000627:therapeutic use; D009895:Opsonin Proteins / Q000097:blood*; D010587:Phagocytosis / Q000276:immunology*; D011008:Pneumococcal Infections / Q000276:immunology / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000276:immunology* / Q000627:therapeutic use; D013296:Streptococcus pneumoniae / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D007074:Immunoglobulin G; D022401:Meningococcal Vaccines; D009895:Opsonin Proteins; D022242:Pneumococcal Vaccines