Antigenic comparison of H3N8 equine influenza viruses belonging to Florida sublineage clade 1 between vaccine strains and North American strains isolated in 2021-2022

Arch Virol. 2023 Feb 19;168(3):94. doi: 10.1007/s00705-023-05720-x.

Abstract

Equine influenza virus strains of Florida sublineage clade 1 (Fc1) have been circulating in North America. In this study, virus neutralization assays were performed to evaluate antigenic differences between Fc1 vaccine strains and North American Fc1 strains isolated in 2021-2022, using equine antisera against A/equine/South Africa/4/2003 (a vaccine strain recommended by the World Organisation for Animal Health) and A/equine/Ibaraki/1/2007 (a Japanese vaccine strain). Antibody titers against four North American Fc1 strains isolated in 2021-2022 were comparable to those against the homologous vaccine strains. These results suggest that current Fc1 vaccine strains are effective against North American strains from 2021-2022.

Keywords: Equine influenza virus; Florida sublineage clade 1; Neutralization assay; Vaccine.

MeSH terms

  • Animals
  • Florida
  • Horse Diseases*
  • Horses
  • Influenza A Virus, H3N8 Subtype*
  • Influenza Vaccines*
  • North America
  • Orthomyxoviridae Infections*
  • Vaccines*

Substances

  • Vaccines
  • Influenza Vaccines