title: Live attenuated nephropathogenic infectious bronchitis virus vaccine provides broad cross protection against new variant strains.
abstract: Infectious bronchitis virus (IBV) infections cause great economic losses to the poultry industry worldwide, and the emergence of new variant strains complicates disease control. The present study investigated the genetic and protectotypic features of newly emerged Korean IBV strains. A phylogenetic analysis showed that several recent isolates formed 2 different clusters (new cluster 1 and 2), which were distinct from other preexisting clusters. New cluster 1 IBV strains represented recombinants between Korean nephropathogenic strain KM91 and the QXIBV strain. New cluster 2 IBV strains showed low amino acid homology (<58.7%) compared with previous isolates. We evaluated the protective efficacy of commercial IBV vaccines (H120 and K2 strain) against these new isolates. In cross-protection studies, the H120 strain did not provide sufficient protection against these variants. However, highly attenuated nephropathogenic IBV vaccine, K2 strain, provided significantly higher levels of protection against variants compared with chickens vaccinated with H120 (P < 0.05 or better). These results indicate that the K2 vaccine could be helpful for the reduction of economic losses caused by newly evolving IBV recombinants (new cluster 1) and variants (new cluster 2).
authors.affiliation: College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701, Korea.
authors.forename: T-H
authors.initials: TH
authors.lastname: Lim
authors.forename: M-S
authors.initials: MS
authors.lastname: Kim
authors.forename: J-H
authors.initials: JH
authors.lastname: Jang
authors.forename: D-H
authors.initials: DH
authors.lastname: Lee
authors.forename: J-K
authors.initials: JK
authors.lastname: Park
authors.forename: H-N
authors.initials: HN
authors.lastname: Youn
authors.forename: J-B
authors.initials: JB
authors.lastname: Lee
authors.forename: S-Y
authors.initials: SY
authors.lastname: Park
authors.forename: I-S
authors.initials: IS
authors.lastname: Choi
authors.forename: C-S
authors.initials: CS
authors.lastname: Song
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002645:Chickens; D018352:Coronavirus Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D056738:Cross Protection; D001351:Infectious bronchitis virus / Q000145:classification / Q000235:genetics; D007668:Kidney / Q000473:pathology / Q000821:virology; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011201:Poultry Diseases / Q000276:immunology / Q000517:prevention & control*; D012367:RNA, Viral / Q000235:genetics; D056910:Republic of Korea; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D017422:Sequence Analysis, DNA; D013047:Specific Pathogen-Free Organisms; D064370:Spike Glycoprotein, Coronavirus; D014132:Trachea / Q000473:pathology / Q000821:virology; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics*; D014765:Viral Vaccines / Q000009:adverse effects / Q000276:immunology*
chemical_list: D008562:Membrane Glycoproteins; D012367:RNA, Viral; D064370:Spike Glycoprotein, Coronavirus; D014613:Vaccines, Attenuated; D014759:Viral Envelope Proteins; D014765:Viral Vaccines