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Antigenic characterization of H3 subtypes of avian influenza A viruses from North America

August 22, 2016

Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable.

Citation Information

Publication Year 2016
Title Antigenic characterization of H3 subtypes of avian influenza A viruses from North America
DOI 10.1637/11086-041015-RegR
Authors Elizabeth Bailey, Li-Pong Long, Nan Zhao, Jeffrey S. Hall, John A Baroch, Jaqueline Nolting, Lucy Senter, Frederick L Cunningham, G Todd Pharr, Larry Hanson, Richard Slemons, Thomas J. DeLiberto, Xiu-Feng Wan
Publication Type Article
Publication Subtype Journal Article
Series Title Avian Diseases
Index ID 70175949
Record Source USGS Publications Warehouse
USGS Organization National Wildlife Health Center