Title: Antigenic evolution of H3N2 influenza A viruses in swine in the United States from 2012 to 2016

Abstract

Background Six amino acid positions (145, 155, 156, 158, 159, and 189, referred to as the antigenic motif; H3 numbering) in the globular head region of hemagglutinin (HA1 domain) play an important role in defining the antigenic phenotype of swine Clade IV (C-IV) H3N2 IAV, containing an H3 from a late 1990s human-to-swine introduction. We hypothesized that antigenicity of a swine C-IV H3 virus could be inferred based upon the antigenic motif if it matched a previously characterized antigen with the same motif. An increasing number of C-IV H3 genes encoding antigenic motifs that had not been previously characterized were observed in the U.S. pig population between 2012 and 2016. Objectives A broad panel of contemporary H3 viruses with uncharacterized antigenic motifs was selected across multiple clades within C-IV to assess the impact of HA1 genetic diversity on the antigenic phenotype. Methods Hemagglutination inhibition (HI) assays were performed with isolates selected based on antigenic motif, tested against a panel of swine antisera, and visualized by antigenic cartography. Results A previously uncharacterized motif with low but sustained circulation in the swine population demonstrated a distinct phenotype from those previously characterized. Antigenic variation increased for viruses with similar antigenic motifs, likely duemore » to amino acid substitutions outside the motif. Conclusions Although antigenic motifs were largely associated with antigenic distances, substantial diversity among co-circulating viruses poses a significant challenge for effective vaccine development. Continued surveillance and antigenic characterization of circulating strains is critical for improving vaccine efforts to control C-IV H3 IAV in U.S. swine.« less

Authors:

Bolton, Marcus J.  ^[1];

• Search DOE PAGES for author "Bolton, Marcus J."
• Search DOE PAGES for ORCID "0000-0002-6933-0548"

Abente, Eugenio J. ^[1]; Venkatesh, Divya ^[2]; Stratton, Jered A. ^[1]; Zeller, Michael ^[3]; Anderson, Tavis K.  ^[1];

• Search DOE PAGES for author "Anderson, Tavis K."
• Search DOE PAGES for ORCID "0000-0002-3138-5535"

Lewis, Nicola S. ^[2]; Vincent, Amy L.  ^[1]

• Search DOE PAGES for author "Vincent, Amy L."
• Search DOE PAGES for ORCID "0000-0002-4953-7285"

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+ Show Author Affiliations

1. National Animal Disease Center, USDA-ARS, Ames Iowa (United States). Virus and Prion Research Unit
2. University of Cambridge, Cambridge (United Kingdom). Department of Zoology
3. National Animal Disease Center, USDA-ARS, Ames Iowa (United States). Virus and Prion Research Unit; Iowa State University, Ames Iowa (United States). College of Veterinary Medicine, Department of Veterinary Diagnostic and Production Animal Medicine

Publication Date:

Sun Oct 07 00:00:00 EDT 2018

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1625885

Grant/Contract Number:  

SC0014664

Resource Type:

Accepted Manuscript

Journal Name:

Influenza and Other Respiratory Viruses

Additional Journal Information:

Journal Volume: 13; Journal Issue: 1; Journal ID: ISSN 1750-2640

Country of Publication:

United States

Language:

English

Subject:

Infectious Diseases; Virology