Hemagglutinin Protein of Influenza B Yamagata Lineage (HA)

The hemagglutinin (HA) protein is a major surface glycoprotein of the Influenza B virus Yamagata lineage, responsible for binding the virus to host cell receptors and facilitating viral entry. The HA protein is also the primary target for neutralizing antibodies and plays a central role in determining antigenic properties and lineage classification. It binds to sialic acid-containing receptors on respiratory epithelial cells and mediates membrane fusion during viral entry. Antigenic drift occurs through point mutations primarily within the HA gene’s globular head region, resulting in new variants that can evade pre-existing immunity. Due to distinct antigenicity between lineages, quadrivalent influenza vaccines include representatives from both Victoria and Yamagata lineages when circulating.

Other names

Influenza B Yamagata HemagglutininB/Yamagata HAYamagata HAHA protein

Vaccines induce neutralizing antibodies that bind to HA, preventing receptor binding and viral entry. Some antiviral drugs may target viral entry or replication.