title: Continuing progress towards a unified nomenclature for the highly pathogenic H5N1 avian influenza viruses: divergence of clade 2.2 viruses.
mesh_terms: D000818:Animals; D001717:Birds; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005585:Influenza in Birds / Q000821:virology*; D010802:Phylogeny; D009626:Terminology as Topic