Young mice infected with SARS-CoV-2 MA were shown to have insterstitial congestion, epithelial damage, inflammatory infiltrate, and peribronchiolar lympocytic inflammation in their airways starting on 2 days post infection (dpi). These were shown to be the primary targets of the virus. The virus was also present in the nasal turbinate epithelium on 2 dpi. These results mirror the trend of the virus replicating in both the upper and lower airways of humans.

• Figure F: 2 dpi lung sections
• Figure G: 4 dpi lung sections
• Figure H: 2 dpi nasal turbinates

Histological samples were stained with immunohistochemistry staining (IHC) to visualize viral nucleocapsid protein, and then they were counterstained with hematoxylin and eosin (H&E).