Fig. 6.

Lung histopathology of unvaccinated or LV::S_Beta-2P-vaccinated HHD-DR1.ACE2^Hu1 mice after inoculation with SARS-CoV-2. Mice are those detailed in the Fig. 5. A. Examples of haematoxylin-eosin saffron staining of whole-lung sections (left, scale bar: 500 μm) and close-up views (right, scale bar: 100 μm), at 4 dpi. Stars mark areas of minimal (bottom) or mild-to-moderate (top) infiltration. In the blow-up panels, red arrows indicate bronchiolar epithelia. While in the bottom blow-up the epithelium is subnormal, in the top panel epithelial degenerative lesions can be seen, e.g., perinuclear clear spaces (green arrow), associated with cells remnants and proteinaceous material in the bronchiolar lumen. B. Heatmap representing the histological scores for: (i) inflammation seriousness, (ii) interstitial syndrome, and (iii) alveolar syndrome, (iv) alteration of bronchial epithelium, and (v) percent of abnormal lung zones.