Continuous monitoring and analysis of the evolution, recombination and
epidemic of avian influenza virus will help to prevent and control the
emergence of new avian influenza virus. The genes of 153 H5N6 avian
influenza viruses selected from our long-term surveillance data and the
GISAID for the 2016-2019 period were dissected in detail. Our analysis
shows that the genes of H5N6 AIVs have been divided into more lineages,
and that mutations leading to amino acid replacement of hemagglutinin
and neuraminidase occurred mainly between 2017 and 2018. All H5N6
viruses are differentiated into at least 20 distinct genotypes derived
from different evolutionary pathways. G1 genotype has replaced other
genotypes to become dominant genotype of AIV. The results of animal
experiments show that H5N6 of different genotypes has high virulence to
mice. which indicates that H5N6 AIVs, especially the reassortment
strains, are a potential threat to public health.