Long distance avian migrants fail to bring 2.3.4.4b HPAI H5N1 into Australia for a second year in a row

There is an ongoing and profound burden of lineage 2.3.4.4b high pathogenicity avian influenza (HPAI) H5N1 on wildlife and poultry, globally. Herein we report the continued absence of HPAI and antibodies against lineage 2.3.4.4b HPAI from October to December 2023, in migratory birds shortly after their arrival in Australia. Given the ever-changing phenotype of this virus, worldwide studies on the occurrence, or here absence of the virus, are of critical importance to understand the virus’ dispersal and incursion risk and development of response strategies.