title: Live attenuated H5N1 vaccine with H9N2 internal genes protects chickens from infections by both highly pathogenic H5N1 and H9N2 influenza viruses.
abstract: BACKGROUND
  The highly pathogenic H5N1 and H9N2 influenza viruses are endemic in many countries around the world and have caused considerable economic loss to the poultry industry. Objectives  We aimed to study whether a live attenuated H5N1 vaccine comprising internal genes from a cold-adapted H9N2 influenza virus could protect chickens from infection by both H5N1 and H9N2 viruses.
  
  
  METHODS
  We developed a cold-adapted H9N2 vaccine virus expressing hemagglutinin and neuraminidase derived from the highly pathogenic H5N1 influenza virus using reverse genetics.
  
  
  CONCLUSIONS
  Chickens immunized with the vaccine were protected from lethal infections with homologous and heterologous H5N1 or H9N2 influenza viruses. Specific antibody against H5N1 virus was detected up to 11 weeks after vaccination (the endpoint of this study). In vaccinated chickens, IgA and IgG antibody subtypes were induced in lung and intestinal tissue, and CD4+ and CD8+ T lymphocytes expressing interferon-gamma were induced in the splenocytes. These data suggest that a live attenuated H5N1 vaccine with cold-adapted H9N2 internal genes can protect chickens from infection with H5N1 and H9N2 influenza viruses by eliciting humoral and cellular immunity.
authors.affiliation: Laboratory of Influenza Research             Institute for Influenza Virus             Laboratory of Public Health, College of Veterinary Medicine, Chungnam National University, Yuseong Gu, Daejeon, Korea.
authors.forename: Nguyen Tai
authors.initials: NT
authors.lastname: Nang
authors.forename: Byung Min
authors.initials: BM
authors.lastname: Song
authors.forename: Young Myong
authors.initials: YM
authors.lastname: Kang
authors.forename: Heui Man
authors.initials: HM
authors.lastname: Kim
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Kim
authors.forename: Sang Heui
authors.initials: SH
authors.lastname: Seo
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002645:Chickens; D015870:Gene Expression; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology; D007070:Immunoglobulin A / Q000032:analysis / Q000097:blood; D007074:Immunoglobulin G / Q000032:analysis / Q000097:blood; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics* / Q000276:immunology*; D053127:Influenza A Virus, H9N2 Subtype / Q000235:genetics* / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis; D007422:Intestines / Q000276:immunology; D008168:Lung / Q000276:immunology; D009439:Neuraminidase / Q000235:genetics / Q000276:immunology; D009976:Orthomyxoviridae Infections / Q000517:prevention & control*; D011201:Poultry Diseases / Q000517:prevention & control; D059386:Reverse Genetics / Q000379:methods; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007252:Influenza Vaccines; D014613:Vaccines, Attenuated; C109963:hemagglutinin, avian influenza A virus; D007371:Interferon-gamma; D009439:Neuraminidase