Influenza A virus hemagglutinin subtype H7N9 (HA (H7N9))

Influenza A virus hemagglutinin subtype H7N9 is the surface glycoprotein found on H7N9 influenza viruses, primarily responsible for binding to sialic acid receptors on host airway epithelial cells[4][5][6]. The receptor specificity of H7N9 HA influences the virus's ability to infect humans, with mutations (such as Q226L, G186V, and others) increasing affinity for human-like α2-6-linked sialic acids, a key adaptation required for efficient human transmission[2][3][4][5][6]. H7N9 HA remains partially avian-tropic, leading to limited sustained transmission in humans, but its dual receptor-binding properties confer pandemic risk[2][5][6]. Therapeutic interventions, particularly vaccines and antibody therapies, are focused on targeting HA to prevent viral entry and fusion[2][4][5][6]. HA's gene and protein are also used as biomarkers in diagnostics and efficacy monitoring.

Other names

Influenza A virus HA subtype H7N9H7 hemagglutininH7N9 hemagglutininHemagglutinin (H7 subtype)

Blockade of HA-receptor interaction (prevents viral binding to host cells); Inhibition of conformational changes needed for membrane fusion (prevention of entry); Neutralization by vaccine-induced antibodies