Figure 9. Concentrations of anti-TcpA and anti-CTB IgG antibodies in sera collected from 6-day old pups born to immunized dams.

One or two pups per dam from the groups immunized with the TcpA-A2-CTB chimera or with TcpA+CTB, TcpA+FliC, CTB, FliC or PBS were sacrificed, on the same day that their siblings were challenged with V. cholerae, to obtain serum for measurements of anti-TcpA and anti-CTB IgG antibody concentrations. Each data point is the serum anti-TcpA or anti-CTB IgG antibody concentration representing the litter of pups from one immunized dam used in the challenge studies with V. cholerae. Filled symbols represent anti-TcpA IgG concentrations, and open symbols represent anti-CTB IgG concentrations. Horizontal lines represent the geometric mean IgG concentration of anti-TcpA or anti-CTB IgG antibodies for all litters of pups born to dams in the indicated immunization group.