Figure 2. Pathogenicity of 2 G4 Eurasian avian-like influenza A(H1N1) swine isolates from pigs in China in BALB/c mice. A) Body weight change of infected mice. B) Survival curve of infected mice. Two groups of five 6-week-old BALB/c mice were inoculated intranasally with A/swine/Jiangsu/HD11/2020(H1N1) (HD11) or A/swine/Anhui/HD21/2020(H1N1) (HD21) at a dose of 106 50% egg infectious dose/50 µL. Another 5 mice mock-infected with phosphate-buffered saline were served as control. Body weight change and survival rate were recorded daily until 14 days postinoculation, and mice that lost ≥25% of the initial body weight were humanely euthanized.