FIG. 4.

Challenge with Vac-gag in mice immunized with the NDV-L-scFv-Gagp41 viruses. Groups of 10 female CxB6 F₁ mice were immunized intranasally with 10⁵ FFU of either NDV-L-scDEC-Gagp41 or NDV-L-scCont-Gagp41. Negative-control mice were inoculated with NDV-L-GFP. Four weeks later, animals were boosted with 10⁶ FFU of the same virus. Four weeks after the boost, five mice per group were challenged with 10⁶ PFU of Vac-Wt or Vac-gag. (A) Six days after the infection with vaccinia viruses, mice were sacrificed, lungs were homogenized in 1 ml of PBS, and vaccinia virus titers in CV-1 cells were determined. (B and C) Weight loss was monitored daily for 6 days after the Vac-gag (B) and Vac-Wt (C) challenges.