FIG. 4.

WN virus-specific reactivity of pre- and postchallenge serum specimens obtained from mice and horses immunized with WN virus DNA vaccine. Pooled serum specimens from the mice and horses used in the experiments were tested at a 1:25 dilution by Western blot analysis using purified WN virion as the antigen. Western blot results obtained with pooled horse sera collected before DNA vaccination (week 0), 5 weeks postvaccination or before virus challenge (week 5), and 2 weeks postchallenge (week 7). Positive horse serum (lane +) was from control horse 16, which had PRNT titer of >1,280 on week 4 after virus challenge. Western blot results obtained with pooled mouse sera collected before DNA vaccination (week 0), 3 and 6 weeks postvaccination or before virus challenge (weeks 3 and 6), and 3 weeks postchallenge (week 9). Mouse HIAF at a 1:250 dilution was used as the positive control (lane +). Sizes are shown in kilodaltons.