Fig. 4.

Mouse lung tissue pathology after IAV infection. Mice were intranasally infected with a non-lethal dose (300 pfu/mouse) of the IAV PR8 strain. Samples were harvested after 6 days. Lung tissue sections prepared from the infected mice were fixed, processed and stained with H&E (a). The lungs of three mice from each treatment group were processed for histology, and results shown were typical for the group. The right two columns were higher magnification images from the left corresponding frames. b Pathologic findings of inflammation and injury were graded for each treatment group