Fig. 4

Prophylactic efficacy of F4 mAb against lethal H9N2-115 challenge. A Schematic representation of the prophylactic test. B Body weight change of mice following virus challenge. C Survival rate of mice after virus challenge. D Immunofluorescence staining of lung slices from mice infected with H9N2-115 at 3 dpi. The viral HA antigen was stained green, and the nucleus was stained blue. Scale bars= 200 μm. E Histopathological examination of the mouse lungs at 3 dpi. The slices were visualized using hematoxylin and eosin (H&E) staining, scale bars = 200 μm