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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #377711

Research Project: Intervention Strategies to Control Influenza A Virus Infection in Swine

Location: Virus and Prion Research

Title: OFFLU animal influenza report: February 2020 to September 2020

item Anderson, Tavis
item ARENDSEE, ZEBULUN - Orise Fellow
item HUFNAGEL, DAVID - Orise Fellow
item YOUNG, KATHARINE - Orise Fellow
item SOUZA, CARINE - Orise Fellow
item KIMBLE, BRIAN - Orise Fellow
item BROWN, IAN - Animal & Plant Health Agency Apha
item ESSEN, STEVE - Animal & Plant Health Agency Apha
item LEWIS, NICOLA - Royal Veterinary College
item Baker, Amy
item COLLINS, SUSAN - Animal & Plant Health Agency Apha
item BYRNE, ALEXANDER - Animal & Plant Health Agency Apha
item PATAPIOU, PARIS - Royal Veterinary College

Submitted to: World Health Organization
Publication Type: Government Publication
Publication Acceptance Date: 9/2/2020
Publication Date: 9/2/2020
Citation: Anderson, T.K., Arendsee, Z.W., Hufnagel, D., Young, K., Souza, C.K., Kimble, B., Brown, I., Essen, S., Lewis, N., Vincent, A.L., Collins, S., Byrne, A., Patapiou, P. 2020. OFFLU animal influenza report: February 2020 to September 2020. World Health Organization. p. 58.

Interpretive Summary:

Technical Abstract: Epidemiologic and phylogenetic analyses of influenza A viruses (IAV) provide rational criteria for vaccine strain selection, control strategies, and may identify viruses with pandemic potential. From the 1918 human influenza pandemic to date, human-to-swine interspecies influenza A virus (IAV) transmission events have repeatedly occurred, some leading to sustained transmission and increased IAV diversity in pig populations. These swine IAV have the potential to be introduced back into the human population if they are substantially different from current human seasonal strains. We quantified the global genetic diversity of swine IAV circulating from 2018 to present, and the genetic diversity of swine IAV in the USA over the past 6 months. We determined how similar the circulating swine IAV diversity was to human IAV vaccines and current candidate vaccine viruses (CVV) that are used in pandemic preparedness efforts. We also antigenically characterized a subset of viruses representing circulating swine IAV using a panel of monovalent anti-sera raised in ferrets against human vaccine strains or CVV strains in hemagglutination inhibition (HI) assays. These data demonstrated that the tested swine IAV was significantly different to the current H1 and H3 components of human IAV vaccines. Additionally, only 7 of the 24 distinct genetic clades detected in swine globally are covered by CVV strains; and the degree to which those CVVs provide protection is dubious given observed genetic differences. We present a comprehensive picture of IAVs infecting swine and how this diversity varies between regions. These analyses demonstrate the dynamic interplay of IAV transmission between humans and swine, and identify genetic groups that should be considered in vaccine strain selection for pandemic preparedness. Testing additional viruses in HI assays with human sera will provide an assessment of human population immunity and quantify the pandemic potential of these swine H1 and H3 viruses.