Fig 1.

Dose–response curves for pertussis, diphtheria, and tetanus antibodies in the International and in-house standards measured by the multiplex assay. (A) WHO International Standard Pertussis (NIBSC 06/140), Tetanus Immunoglobulin (NIBSC TE-3), Diphtheria Antitoxin (NIBSC 10/262), and B. pertussis human serum (NIBSC 89/530); (B) in-house serum IgG standard; (C) in-house breast milk (BM) IgG standard; and (D) in-house BM IgA standard. Data depict mean electrochemiluminescence (ECL) units from duplicate wells versus antibody concentrations for PT (black), PRN (purple), FHA (light blue), FIM 2/3 (light purple), DT (pink), and TT (teal). Representative curves are shown. DT, diphtheria toxoid; FHA, filamentous hemagglutinin; FIM, fimbriae; PT, pertussis toxin; PRN, pertactin; TT, tetanus toxin. Curve parameters, given or assigned unitage, acceptance criteria, and detection limits are shown in Table 1