Influenza A virus (H1N1) pdm09 hemagglutinin (HA)

Hemagglutinin (HA) is a major surface glycoprotein of the Influenza A virus (H1N1) pdm09 strain, which emerged during the 2009 pandemic. It plays a critical role in the viral life cycle by mediating binding to sialic acid receptors on host respiratory epithelial cells and facilitating the fusion of the viral envelope with the endosomal membrane (UniProt: P03452). HA is the primary antigen targeted by seasonal and pandemic influenza vaccines, inducing neutralizing antibodies that block viral entry (PubMed: 20147505). Because of its high rate of mutation, known as antigenic drift, the protein is constantly monitored to update vaccine compositions to match circulating strains (CDC, 2023). Therapeutic strategies targeting HA include monoclonal antibodies and small-molecule fusion inhibitors like Umifenovir, which are designed to prevent infection or reduce disease severity (PubMed: 30639432).

Other names

H1N1pdm09 HAHemagglutininH12009 pandemic H1N1 hemagglutininA(H1N1)pdm09 hemagglutininInfluenza A virus hemagglutinin

Inhibition of viral attachment to host cell sialic acid receptors or prevention of the pH-dependent conformational change required for membrane fusion (PubMed: 30639432).