Fig. 1.

Distinct pathogenicity of circulating CC063, CC077, CC072, CC080, CC085, SHZH98, and FY0805 or BrCr viruses in neonatal mice. Newborn ICR mice were infected with indicated viruse (10^6.5 CCID₅₀/ml). Negative control mice were inoculated with MEM instead of virus. Survival rates and mean clinical scores were continually observed for 21 days after infection. The results are from three independent experiments, and each litter contained 8-10 mice. The mean clinical symptoms were scored as follows: 0, healthy; 1, lethargy or weakness; 2, wasting; 3, limb shake; 4, paralysis in hind limb; 5, moribund or dead