Evolution of the H9N2 influenza genotype that facilitated the genesis of the novel H7N9 virus

Significance The emergence of human infection with a novel H7N9 avian influenza reassortant in China raises a pandemic concern. However, it is not fully understood how these H9N2 chicken viruses facilitated the genesis of the novel H7N9 viruses. Here we show that a “fittest” genotype (G57) emerged w... View More