Vascular dynamics in the lungs of mice infected with SARS-CoV-2. Mice were infected with 2.5 × 10⁴ pfu NG-SARS-CoV-2 via IN. (A) IVM images (original magnification ×20) of the lungs of hACE2 AC70 mice uninfected or infected with NG-SARS-CoV-2 showing platelets (anti-CD49b, blue) in the vasculature (day 6 after infection). Scale bar, 12 μm. The graph represents the quantification of the area covered by platelets per FOV after IVM. (B) IVM images (original magnification ×20) of the lungs of hACE2 AC70 mice uninfected or infected with NG-SARS-CoV-2 after the administration of 70 000 MW dextran-rhodamine. Scale bar, 12 μm. (C) IVM images (original magnification ×20) of the lungs of hACE2 AC70 and hACE2 K18 mice infected with NG-SARS-CoV-2, showing areas with infected cells (green). The asterisk indicates the epithelial lining the alveoli and the filled arrow indicates cells lining the capillaries. Scale bars, 34 μm (left) and 12 μm (right). (D) Quantification of the area covered by platelets per FOV after IVM in hACE2 K18 mice uninfected and infected with NG-SARS-CoV-2 (day 6 after infection). (E) Quantification of the number of neutrophils per FOV after IVM in hACE2 K18 mice infected with NG-SARS-CoV-2 (day 6 after infection). Comparison between FOVs without infected cells vs FOVs with infected cells. Each dot in the graphs represents 1 FOV. (F) IVM image (original magnification ×10) of the lungs of hACE2 AC70 mice infected with NG-SARS-CoV-2 showing PKH-alveolar macrophages (AMs) (red) in the alveolar space (day 6 after infection). Scale bar, 50 μm. (G) Quantification of AM displacement in uninfected and infected mice. Colors represent individual mice. n = 3 mice per group. (H) Hematoxylin and eosin staining of lung sections from hACE2 AC70 mice uninfected and infected with NG-SARS-CoV-2. Data (as applicable) are represented as mean ± SD. Unpaired Student t test was performed for statistical analysis. ∗P < .05; ∗∗∗∗P < .001.