Influenza A viruses (IAVs) in swine are a source of risk to human beings due to their high genetic diversity and absence of population-level immunity. A recent Nature Communications study characterizes influenza viruses, with a particular focus on the α-H1N2 virus, to determine their potential to cause a future pandemic. Study: Potential pandemic risk of circulating swine H1N2 influenza viruses .
Image Credit: Fahroni / Shutterstock.com Influenza viruses possess the ability to evolve specific traits, which facilitates persistent transmission to new species. Although wild aquatic birds are the primary natural reservoir for these virus, pigs can also act as critical hosts and mixing vessel for viral gene segments of IAVs.
This poses a threat to future pandemics, thus emphasizing the importance of monitoring and characterizing circulating swine viruses. Neuraminidase (NA) and hemagglutinin (HA), which evolve seasonally due to antigenic drift, are key determinants of virus transmissibility, infectivity, host specificity, and pathogenicity. Three endemic IAV subtypes, including swH1N1, swH1N2, and swH3N2, predominate in swine.
The H1 classical swine lineage (1A) comprises the α-H1 (1A.1), β-H1 (1A.2), and γ-H1 (1A.
3) clades, whereas the swine lineage (1B) includes the δ-H1 (1B.2) clades. In the United States, human infections have been primarily due to 18 H1N1, 35 H1N2, and 439 H3N2.
A reassortment between swine-, avian-, and human-origin viruses has been observed in recent s.
