Characterization of antibody titers raised against CPS-CRM197, Hcp1, and TssM. C57BL/6 mice (n = 6 per group) were immunized on days 0, 21, and 35 with adjuvant only (Alhydrogel/CpG), conjugate only, Hcp1 only, TssM only, conjugate plus Hcp1, or conjugate plus TssM. Immune serum samples were collected for testing on day 42. ELISAs were used to quantitate serum IgM, IgG, IgG1, and IgG2b titers against (a) CPS, (b) Hcp1, and (c) TssM. Bars represent geometric means with 95% confidence intervals. “Conjugate” is CPS-CRM197; LOD, limit of detection.