Fig. 1.
Vaccinia-H5N1 vaccine protects against group 1 and group 2 viruses. (A) BALB/c mice were vaccinated subcutaneously twice, 3 wk apart with 107 pfu of indicated vaccines (Wyeth/IL-15/5Flu, Wyeth/mut-IL-15/5Flu, wild-type Wyeth, or PBS). Mice were challenged 3 wk later with influenza viruses, (B) H7N7 (10 LD50, 1 × 103TCID50), (C) H3N2 (40 LD50, 4.72 × 105 TCID50), or (D) H1N1 (40 LD50, 9.5 × 105 TCID50). Mice were monitored for survival for 14 d following infection (n = 5–11 mice). Experiments were repeated at least twice.