FIG. 4.

Immune protection from lethal intranasal vaccinia virus challenge. Groups of five mice were inoculated with PBS (PBS-100), LC16m8 (LC-100 and LC-250), or Dryvax (Dryv-100 and Dryv-250). After 6 weeks, mice were challenged intranasally with vaccinia virus strain WR at 100 LD₅₀ (“-100” groups) (3.2 × 10⁶ PFU) or 250 LD₅₀ (“-250” groups) (8.0 × 10⁶ PFU) and weighed daily over a 2-week period. Changes in body weight postchallenge (A) and the percentage of surviving animals in each group after the 2-week monitoring period (B) are shown. Data are representative of two identical experiments.