influenza A virus subtype H1N1 vaccine

An influenza vaccine specifically designed to provide active immunization against the H1N1 subtype of the Influenza A virus, particularly the strain responsible for the 2009 pandemic. These vaccines are typically monovalent and formulated as inactivated split-virion, surface antigen, or live-attenuated preparations. During the 2009 pandemic, several manufacturers developed adjuvanted versions, such as **Arepanrix** and **Pandemrix** (using the AS03 oil-in-water emulsion) and **Focetria** (using MF59), to enhance immunogenicity and allow for dose sparing. The vaccine works by inducing the production of neutralizing antibodies against the viral hemagglutinin (HA) protein. These antibodies block the virus from binding to sialic acid receptors on host respiratory epithelial cells, thereby preventing viral entry and subsequent infection.

Brand names

ArepanrixPandemrixFocetriaCelvapan

Other names

A/H1N1 vaccineH1N1 vaccineH-1N1 vaccineH 1N1 vaccinepandemic H1N1 vaccineswine flu vaccine