FIG 4.

Polymerase and neuraminidase activities of endemic and different reassortant H3N2 viruses. (A) Comparison of polymerase activities of endemic and different reassortant H3N2 viruses containing 3 or 5 genes from pH1N1 virus in 293T cells at 37°C. (B) Comparison of neuraminidase activities of different reassortant and endemic H3N2 swine viruses with that of the 2009 pandemic H1N1 virus. For each virus, three independent replicate experiments were conducted. The error bars represent SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001. TRIG, North American triple-reassortant internal gene; pH1N1, 2009 pandemic H1N1 virus-like gene; CA09, A/California/04/2009.