Swine influenza A virus (H1N1) (H1N1)

Swine influenza virus H1N1 is a subtype of the Influenza A virus that primarily circulates in swine populations but is capable of zoonotic transmission to humans, most notably causing the 2009 swine flu pandemic (CDC, 2023). As an enveloped, negative-sense RNA virus, its genome encodes several proteins that are critical for its life cycle and serve as primary therapeutic targets. Hemagglutinin (HA) mediates binding to host cell sialic acid receptors, while Neuraminidase (NA) facilitates the release of progeny virions by cleaving those same receptors (Nature, 2009). Current clinical management relies heavily on neuraminidase inhibitors such as oseltamivir and zanamivir, as well as the cap-dependent endonuclease inhibitor baloxavir marboxil (DrugBank, 2024). The virus is prone to rapid evolution through antigenic drift and shift, necessitating annual vaccine updates and constant monitoring for the emergence of drug-resistant mutations, such as the H275Y substitution in neuraminidase (PubMed, 2021). Additionally, the M2 ion channel protein was historically a target for adamantanes, though most modern H1N1 strains have developed widespread resistance (NIH, 2022).

Other names

Swine fluH1N1pdm09Influenza A virus subtype H1N1Pig fluA(H1N1)pdm09

Neuraminidase inhibition, Cap-dependent endonuclease inhibition, M2 ion channel blockade, Viral fusion inhibition