H9N2 avian influenza virus-like particle vaccine provides protective immunity and a strategy for the differentiation of infected from vaccinated animals

Vaccine. 2011 May 23;29(23):4003-7. doi: 10.1016/j.vaccine.2011.03.067. Epub 2011 Apr 2.

Abstract

In the present study, virus-like particles (VLPs) were evaluated as a candidate poultry vaccine against avian influenza virus (AIV) subtype H9N2. Specific pathogen-free chickens received a single injection of the VLP vaccine expressing HA and M1 protein of AIV H9N2 (H9 HA VLP) at escalating doses in the presence or absence of ISA70 water-in-oil adjuvant. At 3 weeks post vaccination, we performed hemagglutination inhibition (HI) test and enzyme-linked immunosorbent assay (ELISA) to determine serological immune responses, and challenge studies using SPF chickens. A single dose of H9 HA VLP vaccine induced high levels of HI antibodies and lowered frequencies of virus isolation after the wild-type virus challenge. The addition of ISA70 adjuvant significantly increased the immunogenicity of H9 HA VLP vaccines. Furthermore, it allows differentiation of AIV-infected chickens from vaccinated chickens with an ELISA using nucleocapsid antigen, which offers a promising strategy to differentiate infected from vaccinated animals (DIVA). These results provide support for continued development of the VLP as an animal vaccine against influenza virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Viral / blood*
  • Chickens / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Hemagglutination Inhibition Tests
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / immunology
  • Influenza A Virus, H9N2 Subtype / genetics
  • Influenza A Virus, H9N2 Subtype / immunology*
  • Influenza A Virus, H9N2 Subtype / isolation & purification
  • Influenza A Virus, H9N2 Subtype / pathogenicity
  • Influenza Vaccines / administration & dosage
  • Influenza Vaccines / genetics
  • Influenza Vaccines / immunology*
  • Influenza in Birds / immunology
  • Influenza in Birds / prevention & control*
  • Influenza in Birds / virology
  • Poultry Diseases / immunology
  • Poultry Diseases / prevention & control
  • Poultry Diseases / virology
  • Specific Pathogen-Free Organisms
  • Vaccination / veterinary*
  • Vaccines, Virus-Like Particle / administration & dosage
  • Vaccines, Virus-Like Particle / genetics
  • Vaccines, Virus-Like Particle / immunology*
  • Viral Matrix Proteins / genetics
  • Viral Matrix Proteins / immunology

Substances

  • Antibodies, Viral
  • Hemagglutinin Glycoproteins, Influenza Virus
  • Influenza Vaccines
  • M1 protein, Influenza A virus
  • Vaccines, Virus-Like Particle
  • Viral Matrix Proteins
  • hemagglutinin, avian influenza A virus