Swine influenza A virus (H1N1 and H3N2) (SIV)

Swine influenza virus (SIV) refers to Influenza A virus strains endemic in pigs, primarily H1N1 and H3N2 subtypes, which are zoonotic pathogens capable of causing human respiratory disease (CDC, 2023; WHO, 2023). These viruses belong to the Orthomyxoviridae family and feature an enveloped structure with a segmented, negative-sense RNA genome (NIH, 2021). The viral life cycle depends on key proteins: Hemagglutinin (HA) for host cell binding and Neuraminidase (NA) for the release of new viral particles (NCBI, 2022). Therapeutic agents target these specific processes; for example, oseltamivir and zanamivir act as neuraminidase inhibitors to prevent viral spread, while baloxavir marboxil inhibits the cap-dependent endonuclease required for viral mRNA synthesis (DrugBank, 2024). A major challenge in managing these viruses is the rapid emergence of resistance, such as the H275Y mutation in NA, and the potential for genetic reassortment which can lead to pandemic strains (PubMed, 2022).

Other names

Swine-origin influenza virusS-OIVPig fluH1N1vH3N2vSwine-origin H1N1Swine-origin H3N2

Neuraminidase inhibition (prevents viral release), cap-dependent endonuclease inhibition (blocks viral mRNA synthesis), and M2 ion channel blockade (prevents viral uncoating) (DrugBank, 2024; NIH, 2021).