Anti-Influenza A, HA (Clone HA-2B9) - Purified No Carrier Protein (H293-GRP)

Influenza A causes large numbers of infections and deaths annually, necessitating broad research into vaccines and therapeutics1. Influenza A viruses are classified into subtypes based on the antigenicity of hemagglutinin (HA), the predominant glycoprotein found on the viral surface. There are 18 HA subtypes, which are subdivided into two groups: Group 1 (H1, H2, H5, H6, H8, H9, H11, H12, H13, H16, H17 and H18) and Group 2 (H3, H4, H7, H10, H14 and H15). HA has a receptor binding function that promotes viral entry by engaging sialylated glycan receptors on host cells and enabling host membrane fusion. HA is constantly evolving to escape herd immunity and this can result in pandemics. HA is a homotrimer consisting of two domains: a globular, antigenically variable head and a more conserved, membrane-proximal stem1,2. Neutralizing antibodies targeting the head domain are typically restricted to within subtype, while antibodies targeting the stem can act more broadly across subtypes2. Although most anti-HA antibodies are strain-specific, antibodies with broad neutralizing activity against multiple strains or subtypes have been found1. These broadly neutralizing antibodies are of research interest because they may enable the development of a universal influenza vaccine and/or monoclonal antibody therapy1,3. Characterization of HA-peptide antibody led to the identification of the commonly used HA-tag, a linear epitope of nine amino acids used for protein purification and labeling1. This epitope is not clinically useful because it is inaccessible in the native HA conformation.