A Bivalent Live Attenuated Influenza Virus Vaccine Protects against Drifted H1N2 and H3N2 Clinical Isolates in Swine

Viruses. 2022 Dec 23;15(1):46. doi: 10.3390/v15010046.

Abstract

Influenza A viruses (IAVs) can cause a highly contagious respiratory disease for many mammalian species. In pigs, IAVs cause high morbidity and low mortality disease in susceptible populations that can have significant financial and production impacts. They can also present opportunities for mutations and gene reassortment, producing influenza strains with pandemic potential. Therefore, it is very important to prevent and control influenza infection in pigs, and the chief way to do so is through vaccination. The subtypes of IAV most prevalent in swine across the world are H1N1, H1N2, and H3N2; however, genetic diversity of these viruses can vary greatly by region. We previously developed an elastase-dependent bivalent live attenuated vaccine using two Canadian swine influenza A virus (swIAV) isolates, A/Swine/Alberta/SD0191/2016 (H1N2) [SD191] and A/Swine/Saskatchewan/SD0069/2015 (H3N2) [SD69], which provided protection against homologous strains. In this study, we demonstrate that this vaccine extends protection in pigs to more current, drifted non-homologous H1N2 and H3N2 strains, A/Swine/MB/SD0467/2019 (H1N2) [SD467] and A/Swine/AB/SD0435/2019 (H3N2) [SD435]. The vaccine elicited a robust immune response in the serum and the lung and reduced viral replication as well as lung pathology associated with these strains. Therefore, this bivalent vaccine remains a strong candidate that would be beneficial to the swine influenza vaccine market in North America.

Keywords: influenza; swine; vaccine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alberta
  • Animals
  • Antibodies, Viral
  • Humans
  • Influenza A Virus, H1N1 Subtype* / genetics
  • Influenza A Virus, H1N2 Subtype
  • Influenza A Virus, H3N2 Subtype
  • Influenza A virus* / genetics
  • Influenza Vaccines* / genetics
  • Influenza, Human*
  • Mammals
  • Orthomyxoviridae Infections* / prevention & control
  • Orthomyxoviridae Infections* / veterinary
  • Swine
  • Swine Diseases*
  • Vaccines, Attenuated

Substances

  • Influenza Vaccines
  • Vaccines, Attenuated
  • Antibodies, Viral

Grants and funding

This research was funded by the Agriculture Development Fund (ADF), Ministry of Saskatchewan Agriculture. L.A. is partially supported by the Vaccinology and Immunotherapeutics (V&I) Scholarship from the School of Public Health, the University of Saskatchewan. VIDO receives operational funding from the Government of Saskatchewan through Innovation Saskatchewan and the Ministry of Agriculture and from the Canada Foundation for Innovation through the Major Science Initiatives for its CL3 facility (InterVac).