Avian influenza virus hemagglutinin H5 (H5 HA) (H5 HA)

Avian influenza virus hemagglutinin H5 is a critical surface glycoprotein of the influenza A virus, primarily responsible for viral attachment to host cells and subsequent membrane fusion. It specifically recognizes alpha-2,3-linked sialic acid receptors, which are prevalent in the avian gastrointestinal tract and the human lower respiratory tract, contributing to the severe pneumonia often seen in zoonotic H5N1 infections. As a vaccine antigen, H5 HA is the primary target for inducing neutralizing antibodies that block viral entry by targeting the globular head or the conserved stem region of the protein. However, the high rate of antigenic drift in H5 clades poses a significant challenge for vaccine efficacy, often necessitating the use of adjuvants to enhance immunogenicity and the development of pre-pandemic stockpiles. Current therapeutic strategies focus on both traditional inactivated vaccines and novel platforms like mRNA and recombinant proteins to provide broad protection against emerging H5 strains.

Other names

Hemagglutinin H5H5N1 hemagglutininHA5Influenza A virus H5 hemagglutininH5 glycoprotein

Induction of neutralizing antibodies that block the receptor-binding site or the fusion machinery of the hemagglutinin protein to prevent viral attachment and entry.