摘要
The relentless march of a highly pathogenic avian influenza virus(HPAIV)strain,known as H5N1,to become an unprecedented panzootic continues unchecked.The leap of H5N1 clade 2.3.4.4b from Eurasia and Africa to North America in 2021 and its further spread to South America and the Antarctic have exposed new avian and mammalian populations to the virus and led to outbreaks on an unrivaled scale.The virus has infected wild birds across vast geographic regions and caused wildlife deaths in some of the world's most biodiverse ecosystems.
