FIG. 3.

T-cell immunity generated by DNA or live viral vaccines. Groups of C3H/HeN mice (n = 3) were immunized three times at 3-week intervals with pE or pcDNA3 or sublethally immunized twice at 3-week intervals with 6.0 × 10⁵ PFU of JEV Beijing-1 as described in Materials and Methods. One week after the last immunization, splenocytes were examined for JEV E-specific proliferative responses (A) and CTL activities (B) as described in Materials and Methods. The data are representative of three independent experiments. i.m., intramuscular.