Figure 1.

SARS-CoV-2 infection via the intranasal route results in a rapid development of clinical disease and mortality. 25 AC70 mice were intranasally inoculated with 1 × 10³ TCID₅₀ of SARS-CoV-2 strain US-WA-1/2020 in 2% fetal bovine serum-supplemented cell media (2-MEM) and then five mice were sacrificed each day for 5 days post-infection. (A) Significant weight loss rapidly developed starting on 4 dpi, correlating with (B) the onset of severe clinical signs of disease. (C) The onset of clinical disease quickly advanced to near full mortality at 5 dpi Weight changes were expressed as the mean percent changes in infected animals relative to the initial weights at 0 dpi Error bars represent standard errors of the mean (SEM). ****p < 0.0001. These were the representative results of one out of two independent experiments.