Hemagglutinin and Neuraminidase of H5N1 Influenza A Virus (H5N1 Antigens)

The H5N1 influenza virus antigens primarily consist of two major surface glycoproteins: Hemagglutinin (H5) and Neuraminidase (N1). Hemagglutinin is responsible for viral attachment to host cells by binding to alpha-2,3-linked sialic acid receptors and mediating the fusion of the viral envelope with the host endosomal membrane for entry. Neuraminidase acts as a sialidase enzyme that cleaves sialic acid residues from both host cell surfaces and progeny virions, thereby facilitating the release and spread of new virus particles. These antigens are the primary targets for seasonal and pre-pandemic vaccines, as well as several classes of antiviral drugs including neuraminidase inhibitors like oseltamivir and zanamivir. Because H5N1 is a highly pathogenic avian influenza (HPAI) strain, the structural evolution of these antigens through mutation or genetic reassortment is a major factor in host specificity, virulence, and the potential for a global pandemic.

Other names

H5N1 surface glycoproteinsH5N1 viral antigensAvian influenza A H5N1 antigensH5 HemagglutininN1 NeuraminidaseHighly Pathogenic Avian Influenza H5N1 proteins

Neuraminidase inhibition to prevent viral egress; Hemagglutinin-mediated fusion inhibition to prevent viral entry; M2 ion channel blockade to prevent viral uncoating; Neutralizing antibody binding for vaccine-induced protection.