Equine Influenza Serological Methods

  • Thomas M. ChambersEmail author
  • Stephanie E. Reedy
Part of the Methods in Molecular Biology book series (MIMB, volume 2123)


Serologic tests for equine influenza virus (EIV) antibodies are used for many purposes, including retrospective diagnosis, subtyping of virus isolates, antigenic comparison of different virus strains, and measurement of immune responses to EIV vaccines. The hemagglutination inhibition (HI) assay, single radial hemolysis (SRH), and serum micro-neutralization tests are the most widely used for these purposes and are described here. The presence of inhibitors of hemagglutination in equine serum complicates interpretation of HI assay results, and there are alternative protocols (receptor-destroying enzyme, periodate, trypsin-periodate) for their removal. With the EIV H3N8 strains in particular, equine antibody titers may be magnified by pre-treating the HI test antigen with Tween-80 and ether. The SRH assay offers stronger correlations between serum antibody titers and protection from disease. Other tests are sometimes used for specialized purposes such as the neuraminidase-inhibition assay for subtyping, or ELISA for measuring different specific antibody isotypes, and are not described here.

Key words

Antibody Hemagglutination inhibition Hemolysis Neutralization Influenza 


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Copyright information

© This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply. 2020

Authors and Affiliations

  1. 1.Maxwell H. Gluck Equine Research Center, Department of Veterinary ScienceUniversity of KentuckyLexingtonUSA

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