Fig. 3
Symptoms and viral shedding in male hamster intranasally inoculated with varied doses of SARS-CoV-2. a Schematic diagram of SARS-CoV-2 infection and animal operations. Male hamsters were nasally inoculated with 102–105 PFU of SARS-CoV-2, respectively. Body weight and symptoms were daily observed. Nasal washings were daily collected. Animals were euthanized at 3, 5, and 7 dpi for lung histological analysis, respectively. b Change of body weight. c PCR detection for viral RNA levels in nasal washings. d Daily observation for typical symptoms includes weakness, piloerection, hunched back, and abdominal respiration. Each symptom was scored based on the severity of none (0), moderate (1), mild (2), severe (3), and very severe (4), respectively. Detailed data of individual animals in (b–d) were shown in Supplementary Figs. 10–12. e Ratio of lung weight to body weight of indicated male hamsters at 3, 5, and 7 dpi, respectively. Hamsters without SARS-CoV-2 infection were set as mock controls (n = 2/group). f Comprehensive pathological score of lung sections for lung sections collected from male hamster nasally inoculated with 102–105 PFU of SARS-CoV-2 at 3, 5, and 7 dpi, respectively. For each group, different lung lobes collected from two individual animals were collected at 3, 5, and 7 dpi, respectively. Detailed images of lung lobes were shown in Supplementary Fig. 16
