FIG. 3.

Serum antibody responses in mice following intranasal inoculation with the RB50 or LPaV strain. Total Bordetella-specific IgG titers were determined by ELISA using either RB50 or LPaV whole cells as the antigen. The bars indicate the mean titers for 4 to 7 mice, and the error bars indicate the standard deviations. A statistical analysis was carried out using an unpaired two-tailed Student t test to compare the antibody titers obtained for sera of RB50-infected mice to the antibody titers obtained for sera from LPaV-infected mice. The asterisks indicate that the P value is ≤0.0005.