influenza A (H5N1) antigen

Influenza A (H5N1) antigen is the active immunogenic component of vaccines designed to protect against infection with the highly pathogenic avian influenza A (H5N1) virus. The antigen is typically a purified and inactivated hemagglutinin protein derived from the H5 subtype of the virus. It is produced by propagating the virus in embryonated hen’s eggs or mammalian cells, followed by purification and inactivation to eliminate infectivity[2][3][6]. The mechanism of action involves stimulating an immune response—primarily antibody production—against the viral hemagglutinin protein. This prevents viral entry into host respiratory cells upon exposure to wild-type H5N1 virus[2][3][6]. The antigen is often formulated with adjuvants such as AS03 (an oil-in-water emulsion containing squalene and α-tocopherol), which enhances immunogenicity and allows for dose sparing[2][3][6]. Vaccines containing this antigen are indicated for pre-exposure prophylaxis against avian flu in individuals at high risk of exposure.

Brand names

AudenzPrepandrix

Other names

influenza A (H5N1) vaccineH5N1 antigenH-5N1 antigenH 5N1 antigenavian influenza H5N1 vaccineinactivated H5N1 split-virion vaccine