title: Distribution of avian influenza H5N1 viral RNA in tissues of AI-vaccinated and unvaccinated contact chickens after experimental infection.
abstract: Avian influenza due to highly pathogenic avian influenza (HPAIV) H5N1 virus is not a food-borne illness but a serious panzootic disease with the potential to be pandemic. In this study, broiler chickens were vaccinated with commercial H5N1 or H5N2 inactivated vaccines prior to being challenged with an HPAIV H5N1 (clade 2.2.1 classic) virus. Challenged and non-challenged vaccinated chickens were kept together, and unvaccinated chickens served as contact groups. Post-challenge samples from skin and edible internal organs were collected from dead and sacrificed (after a 14-day observation period) birds and tested using qRT-PCR for virus detection and quantification. H5N1 vaccine protected chickens against morbidity, mortality and transmission. Virus RNA was not detected in the meat or edible organs of chickens vaccinated with H5N1 vaccine. Conversely, H5N2 vaccine did not confer clinical protection, and a significant virus load was detected in the meat and internal organs. Phylogenetic analysis showed that the H5N1 virus vaccine and challenge virus strains are closely related. The results of the present study strongly suggest a need for proper selection of vaccines and their routine evaluation against newly emergent field viruses. These actions will help to reduce human exposure to HPAIV H5N1 virus from both infected live birds and slaughtered poultry. In addition, rigorous preventive measures should be put in place in order to minimize the public-health risks of avian influenza at the human-animal interface.
authors.affiliation: National Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, P.O. Box 246, Dokki, Giza 12618, Egypt. mkahassan@hotmail.com
authors.forename: Mohamed K
authors.initials: MK
authors.lastname: Hassan
authors.forename: Walid H
authors.initials: WH
authors.lastname: Kilany
authors.forename: E M
authors.initials: EM
authors.lastname: Abdelwhab
authors.forename: Abdel-Satar
authors.initials: AS
authors.lastname: Arafa
authors.forename: Abdullah
authors.initials: A
authors.lastname: Selim
authors.forename: Ahmed
authors.initials: A
authors.lastname: Samy
authors.forename: M
authors.initials: M
authors.lastname: Samir
authors.forename: Yvon
authors.initials: Y
authors.lastname: Le Brun
authors.forename: Yilma
authors.initials: Y
authors.lastname: Jobre
authors.forename: Mona M
authors.initials: MM
authors.lastname: Aly
mesh_terms: D000818:Animals; D002645:Chickens; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000235:genetics / Q000276:immunology*; D053125:Influenza A Virus, H5N2 Subtype / Q000145:classification / Q000235:genetics / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology; D005585:Influenza in Birds / Q000276:immunology* / Q000517:prevention & control / Q000635:transmission / Q000821:virology; D007251:Influenza, Human / Q000517:prevention & control / Q000635:transmission / Q000821:virology; D008460:Meat / Q000032:analysis / Q000821:virology; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics* / Q000276:immunology; D014611:Vaccination
chemical_list: D007252:Influenza Vaccines; D012367:RNA, Viral