FIG 1.

CC strains demonstrate different susceptibility to SARS-CoV infection and disease. Age-matched female mice (n = 4) of 5 different CC strains (CC005, CC011, CC020, CC068, and CC074) were infected with 1 × 10⁴ PFU and monitored for weight loss until 4 dpi. An additional group of age-matched CC011 and CC074 (both sexes) were infected with 1 × 10⁴ PFU, and mice were monitored for disease progression until 4 dpi. (A) Weight loss for CC strains CC005, CC011, CC020, CC068, and CC074. (B) Weight loss of the two parental CC strains CC011 and CC074. (C) Percentage survival of the two parental CC strains CC011 and CC074. (D) Lung viral titer of the two parental CC strains CC011 and CC074 on 2 and 4 dpi. (E) Lung congestion score of the two parental CC strains CC011 and CC074 (female 10- to 12-week-old mice were infected with 1 × 10⁴ PFU SARS-CoV MA15; CC011: n = 4 for 2 dpi and n = 6 for 4 dpi; CC074: n = 4 for 2 dpi and n = 6 for 4 dpi, respectively). Data were analyzed using Mann-Whitney test (lung titer and congestion scores); *, P < 0.05.