TABLE 3.

Microscopic lung lesion scoring

Score	Histopathological lesions (0 to 3)
0	Absence of lesion
1	The alveolar septum is slightly widened, and there is a small amount of lymphocyte infiltration. The bronchiolar epithelium is regularly arranged, and there is a small amount of inflammatory cell infiltration around the lumen
2	Light to moderate infiltrates of neutrophils, lymphocytes, and macrophages into the septal wall, bronchus, and alveolar lumen
3	Presence of perivascular or peribronchiolar lymphoplasmacytic hyperplasia and hyperplasia of edema in the alveoli