Concentration-dependent MCPS binding of murine serum Abs induced by immunization. The markers represent the averages of near-equilibrium binding, and the error bars represent the ranges of two determinations. (A) Sera from hosts immunized with MCC conjugate vaccines by Vac1, Vac2, and Vac3 binding to OAc− and OAc+ surfaces. (B) Sera from hosts immunized with PBS, OAc+ fixed bacteria, and OAc− fixed bacteria binding to OAc− and OAc+ surfaces.