Abstract: Swine-to-Ferret Transmission of Antigenically Drifted Contemporary Swine H3N2 Influenza A Virus Is an Indicator of Zoonotic Risk to Humans

Apr 03, 2023

Human-to-swine transmission of influenza A (H3N2) virus occurs repeatedly and plays a critical role in swine influenza A virus (IAV) evolution and diversity. Human seasonal H3 IAVs were introduced from human-to-swine in the 1990s in the United States and classified as 1990.1 and 1990.4 lineages; the 1990.4 lineage diversified into 1990.4.A-F clades. Additional introductions occurred in the 2010s, establishing the 2010.1 and 2010.2 lineages. Human zoonotic cases with swine IAV, known as variant viruses, have occurred from the 1990.4 and 2010.1 lineages, highlighting a public health concern. If a variant virus is antigenically drifted from current human seasonal vaccine (HuVac) strains, it may be chosen as a candidate virus vaccine (CVV) for pandemic preparedness purposes. We assessed the zoonotic risk of US swine H3N2 strains by performing phylogenetic analyses of recent swine H3 strains to identify the major contemporary circulating genetic clades. Representatives were tested in hemagglutination inhibition assays with ferret post-infection antisera raised against existing CVVs or HuVac viruses. The 1990.1, 1990.4.A, and 1990.4.B.2 clade viruses displayed significant loss in cross-reactivity to CVV and HuVac antisera, and interspecies transmission potential was subsequently investigated in a pig-to-ferret transmission study.

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Video: Hendrix Genetics Swine Raises the Bar: Delivering Robust Genetics for Pork Producers

The swine genetics landscape is evolving rapidly, and Hendrix Genetics Swine is leading the way. In this exclusive interview, Bryce Martin discusses how the integration of Hypor, Danish Genetics and the newly introduced Nexus product line is creating one of the industry's most comprehensive genetic portfolios. Producers across Canada, the United States and Europe are facing increasing pressure to improve efficiency, animal health, survivability and profitability, and Hendrix Genetics Swine is responding with genetics designed to meet those challenges.
Martin explains how the strengths of Hypor's balanced and sustainable breeding approach combine with Danish Genetics' reputation for robustness, growth performance and productivity to deliver solutions tailored to a wide range of production systems. The discussion also explores the launch of Nexus 100, a new sow developed from the combined expertise of both genetic programs and designed to improve predictability, survivability and total system profitability. For more information visit: https://swine.hendrix-genetics.com/en/