Stable non-synonymous substitutions on NS gene (NS1 and NS2 proteins) of Qinghai Lake H5N1 influenza virus (Clade 2.2) after successive passages in Muscovy ducks.

Stable non-synonymous substitutions on NS gene (NS1 and NS2 proteins) of Qinghai Lake H5N1 influenza virus (Clade 2.2) after successive passages in Muscovy ducks.