influenza a/hong kong/156/1997(h5n1) virus ns1 gene mutations
h1n1h7n9h7n7h9n2h5n1different virusesmigratory birdsdomestic
airborne transmission of influenza a/h5n1 virus between ferrets
influenza a/hong kong/156/1997(h5n1) virus ns1 gene mutations
characterization of h5n1 influenza virus variants