Connecting the dots between swine influenza A virus surveillance and vaccines

摘要

Influenza A virus (IAV) infection was first recognized in the swine population following the 1918 Spanish flu pandemic in humans with the identification of an H IN 1 virus that became known as the classical swine H1N1. In 1997-98, the incursion of thetriple reassortant viruses with gene segments from human- (HA, NA, and PB1), swine- (NP and M) and avian- (PB2 and PA) adapted viruses changed the landscape of IAV in swine in the US and subsequently around the world.1,2 The establishment of the triplereassortant internal gene (TRIG) constellation is recognized as a critical juncture from that point in time into the present day, during which time we observed the TRIG viruses reassort numerous times to acquire new surface genes in the US ((3, y, 51 and52-H1N1 and H1N2; H2N3), to be exported to new regions (China and South Korea for example), and donate genes to the first human pandemic virus of the 21st century, HlNlp-dm09.3 Concurrent with frequent reassortment has been a dramatic evolution of IAV in swine in the US, resulting in multiple antigenic variants that co-circulate and severely challenge our control measures.