Genetic Diversity of Clade 2.3.4.4b H5Nx High Pathogenicity Avian Influenza Viruses Detected in Korea During the 2025-2026 Winter Season and Pathogenicity of H5N1 and H5N9 Viruses.
Clade 2.3.4.4b H5N1, H5N6, and H5N9 high pathogenicity avian influenza viruses (HPAIVs) were detected in poultry and wild birds during the 2025-2026 winter season in Korea. During this period, 62 H5Nx HPAI outbreaks occurred in poultry, and 63 cases were reported in wild birds. Genome constellation analysis revealed su...