A, Infected mice (nā=ā5 per group) were bled at multiple time-points post-infection and their pooled sera analyzed for total IgM (top) and total IgG (bottom), with triplicate repeats for each time-point. B, Pooled sera were analyzed for CRP-specific IgM and CRP-specific IgG by ELISA in duplicate. C, Balb/c generate a higher titer CRP-specific IgG than do C57Bl/6 mice in response to genetic immunization (pā=ā0.002). Each data point represents one mouse, data pooled from several individual experiments. Balb/c are represented by open squares, solid line; C57Bl/6 mice by closed circles, dashed line. * p<0.05, *** p<0.001 by Student's t test comparing Balb/c and C57Bl/6 models.