FIG 2.

Pathogenicity of IAV-p24 in BALB/c mice. (A) Body weight of the mice infected with IAV-p24 or PR8. Eight-week-old female BALB/c mice were used and the body weight was monitored daily. (B) Survival curves of the mice infected with IAV-p24 or PR8. Mice that lost 25% of initial body weight or showed severe symptoms were scored as dead and euthanized. (C) Viral loads in the lung. At 5 days after infection, mice were sacrificed and the lung tissues were separated and homogenized. Live viral particles were assessed by plaque-forming assay. Data are representative of those from two independent experiments and expressed as the means ± SD (n = 5). Comparisons among groups in panels B and C were conducted using the log rank test and one-way analysis of variance (ANOVA), respectively. *, P < 0.05; **, P < 0.01; ***, P < 0.001.