Protection of chickens against highly lethal H5N1 and H7N1 avian influenza viruses with a recombinant fowlpox virus co-expressing H5 haemagglutinin and N1 neuraminidase genes

Avian Pathol. 2003 Feb;32(1):25-32. doi: 10.1080/0307945021000070688.


Inactivated whole avian influenza virus (AIV) vaccine provides protection against homologous haemagglutinin (HA) subtype virus, but poor protection against a heterologous HA virus. Moreover, it induces chickens to produce antibodies to cross-reactive antigens, especially nucleoprotein, which is limits AIV serological surveillance. In this study, a recombinant fowlpox virus co-expressing HA (H5 subtype) and NA (NI subtype)genes of AIV was evaluated for its ability to protect chickens against intramuscular challenge with a lethal dose of highly pathogenic (HP) AIV. Susceptible chickens were also vaccinated by wing-web puncture with the parent fowlpox vaccine virus. Following challenge 4 weeks later with HPAIV, all chickens vaccinated with recombinant virus were protected, while the chickens vaccinated with either the unaltered parent fowlpox vaccine virus or unvaccinated controls experienced 100% mortality following challenge. This protection was accompanied by the high levels of specific antibody to the respective components of the recombinant vaccine. The above results showed that rFPV-HA-NA could be a potential vaccine to replace current inactivated vaccines for preventing AI.

Publication types

  • Clinical Trial

MeSH terms

  • Animals
  • Antibodies, Viral / immunology
  • Chickens
  • DNA, Recombinant / genetics
  • Fowlpox virus / genetics*
  • Fowlpox virus / physiology
  • Gene Expression
  • Genes, Viral / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / immunology*
  • Influenza A Virus, H5N1 Subtype*
  • Influenza A virus / classification*
  • Influenza A virus / genetics
  • Influenza A virus / immunology*
  • Influenza in Birds / immunology
  • Influenza in Birds / prevention & control*
  • Neuraminidase / genetics
  • Neuraminidase / immunology*
  • Poultry Diseases / immunology
  • Poultry Diseases / prevention & control
  • Time Factors
  • Viral Vaccines / genetics
  • Viral Vaccines / immunology*


  • Antibodies, Viral
  • DNA, Recombinant
  • Hemagglutinin Glycoproteins, Influenza Virus
  • Viral Vaccines
  • hemagglutinin, avian influenza A virus
  • Neuraminidase