FIG. 3.

Induction of fimbria-specific IgA and IgG responses in serum and saliva samples from DNA-immunized mice. Each vaccine was injected biweekly as shown by black arrows for a total of four inoculations. For each sample, the endpoint titer of fimbria-specific antibody was defined as described in Materials and Methods. The results are expressed as means ± standard deviations of log₂ ELISA antibody titers for triplicate wells. Levels of fimbria-specific IgG antibody in serum (A) and of IgA (B) and IgG (C) in saliva samples were determined. i.m., intramuscular.