Weight variation (a), survival rates (b), and replication (c) of novel reassortant IAVs-S in mice. Mice in each group were infected intranasally with 5 × 104 TCID50 of virus in a volume of 50 µL. The body weight and survival rates of mice were measured over 14 days. Virus titers of lung on 3 and 5 days post infection (d.p.i.) were shown as the mean titers of three mice