Toward a unified nomenclature system for highly pathogenic avian influenza virus (H5N1).

Highly pathogenic avian influenza (HPAI) virus (H5N1) has appeared in >60 countries and continues to evolve and diversify at a concerning rate. Because different names have been used to describe emerging lineages of the virus, this study describes a unified nomenclature system to facilitate discussion and comparison of subtype H5N1 lineages.