title: Cross-protective immune responses elicited by a Korean variant of infectious bronchitis virus.
abstract: Infectious bronchitis virus (IBV) infections cause great economic losses to the poultry industry worldwide. IBVs continuously evolve by developing mutations in antigenic sites; therefore, an IBV vaccine that provides broad cross-protection can be a highly relevant and practical method in IBV control strategies. Although some IBV vaccine strains are known to provide protection against multiple IBV serotypes, in general commercially available IBV vaccine strains provide protection against antigenically related viruses but not distinct heterologous viruses. In the present study we characterized the Korean variant IBV K40/09 strain with regard to its immunogenicity and protective efficacy against seven currently circulating IBV serotypes. Three-week-old specific-pathogen-free chickens were intraocularly immunized with the IBV K40/09 strain at 10(3.5) 50% egg infective dose (EID50). Three weeks after immunization all the birds were challenged with seven different strains at 10(4.5) EID50. Chickens immunized with the IBV K40/09 strain showed significantly high levels of protection against all challenge viruses at the trachea and kidney levels. Our results suggest that IBV K40/09 could be useful to ensure IBV vaccine effectiveness owing to its cross-protective ability. Therefore, the IBV K40/09 strain merits consideration as a vaccine candidate to prevent infection as well as the spread of new IBV strains and many IBV variants that have been reported worldwide.
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Byoung-Yoon
authors.initials: BY
authors.lastname: Kim
authors.forename: Dong-Hun
authors.initials: DH
authors.lastname: Lee
authors.forename: Jun-Hyuk
authors.initials: JH
authors.lastname: Jang
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Lim
authors.forename: Soo-Won
authors.initials: SW
authors.lastname: Choi
authors.forename: Ha-Na
authors.initials: HN
authors.lastname: Youn
authors.forename: Jae-Keun
authors.initials: JK
authors.lastname: Park
authors.forename: Joong-Bok
authors.initials: JB
authors.lastname: Lee
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Park
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Choi
authors.forename: Chang-Seon
authors.initials: CS
authors.lastname: Song
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002642:Chick Embryo; D002645:Chickens; D018352:Coronavirus Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D056738:Cross Protection; D001351:Infectious bronchitis virus / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity*; D007668:Kidney / Q000473:pathology; D008969:Molecular Sequence Data; D011201:Poultry Diseases / Q000276:immunology* / Q000821:virology; D056910:Republic of Korea; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013047:Specific Pathogen-Free Organisms; D014132:Trachea / Q000473:pathology; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*; D014774:Virulence
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines