Eosinophil degranulation products persist in the airways of mice subjected to Af sensitization and challenge and are associated with protection from the lethal sequelae of PVM infection. (A) Wild-type B6 mice subjected to Af sensitization and Af or PBS challenge prior to PVM infection on day 0 (see Figure 4A for protocol) and percent eosinophils were evaluated in BAL fluid as shown; P < .0001 for B6-Af vs B6 at all points (not shown on figure); **P < .03 vs percentage eosinophils at day 1. (B) Immunoreactive mEPX detected in mice that were Af sensitized and Af challenged prior to PVM infection only (B6-Af+pvm); P < .0001 for B6-Af vs B6 at all points (not shown on figure), **P < .03 compared with peak levels detected at day 2. (C) RNase activity detected in BAL fluid of mice as described in A; P < .0001 for B6-Af vs B6 at all points (not shown on figure); **P < .03 compared with peak levels detected at day 2. (D) Virus recovery from lung tissue of mice that were Af sensitized and PBS challenged vs Af sensitized and Af challenged prior to PVM infection; *P < .05 compared with recovery at day 1. (E) Percent weight change of mice subjected to Af sensitization and PBS or Af challenge prior to PVM infection. Arrow a. denotes transient weight loss at day 2 experienced by the Af-sensitized and Af-challenged mice, and arrow b. designates loss of PVM-infected, Af-sensitized, PBS-challenged mice at days 7 and 9. (F) Survival of Af-sensitized and PBS- or Af-challenged mice prior to PVM infection on day 0; n = 5 mice per group; *P < .03 (log-rank).