The potential oncogenic activity of influenza A virus in lungs of mice.

Adult male CD1 mice were inoculated with chicken egg-propagated influenza type A/PR8/34 virus. Fully developed pulmonary pneumonia was found 7 d after the infection. In addition to the pneumatic condition, pronounced thickening of the bronchiolar epithelium denoting hyperplastic and dysplastic transformation of the epithelial cells were also observed.