Multilaboratory Evaluation of a Viability Assay for Measurement of Opsonophagocytic Antibodies Specific to the Capsular Polysaccharides of Streptococcus pneumoniae

• DOI: 10.1128/cdli.10.6.1019-1024.2003
• Publication Date: 2003-11-07T20:11:30Z
• Authors: Sandra Romero-Ste...; Carl Frasch; Nelydia Concepcion; David Goldblatt; Helena Käyhty; Merja Väkeväinen; Craig Laferriere; Dominique Wauters; Moon H. Nahm; Mark F. Schinsky; Brian D. Plikaytis; George M. Carlone
• Keywords: Serial dilution; Antibody titer

ABSTRACT Opsonophagocytosis is a correlate of protection that measures the functional activity vaccine-induced antibodies. A standardized opsonophagocytosis assay (OPA) should be used as part evaluation current and future pneumococcal (Pnc) polysaccharide (Ps)-based vaccines. We enrolled five laboratories to evaluate previously viability OPA. Each laboratory was provided with detailed OPA protocol, seven target Pnc strains (serotypes 4, 6B, 9V, 14, 18C, 19F, 23F), two quality control sera 12 paired (blinded) from adult donors who received one dose 23-valent Ps vaccine. Laboratories sent their results Centers for Disease Control Prevention analysis. Sera were tested in duplicate (single run), averaged yield single titer (≥50% killing) each serum sample. The percentage within or dilutions calculated median determined serotype. In general, capable detecting titers at least 75 88%, respectively, tested. level agreement varied depending on participating (overall = 0.8 [99% confidence interval 0.75 0.85]). All reported dilution expected titer. conclude this can done multiple high degree interlaboratory reproducibility.