FIG. 5.

Immunogenicities and protective efficacies of heterologous prime-boost regimens. Groups of C57BL/6 mice (n = 8/group) were immunized i.m. at week 0 with 50 μg Gag WT or Gag dAL11 DNA vaccine and boosted at week 4 with 10⁶ vp of rAd5 expressing Gag WT. Control mice received a sham plasmid and an empty rAd5 vector. (A) AL11- and KV9-specific CD8⁺ T-lymphocyte responses by IFN-γ ICS assays 2 weeks after the boost immunization at week 6. (B) Mice were challenged i.p. at week 10 with 5 × 10⁶ PFU of vaccinia virus-Gag, and vaccinia virus titers in ovaries were assessed on day 6 after challenge. Virus titers in both vaccinated groups (*) were significantly lower than those in the sham control group (P < 0.001). Virus titers were lower in mice primed with the Gag dAL11 DNA vaccine than in mice primed with the Gag WT DNA vaccine (P < 0.05). Error bars indicate standard errors.