title: Successful cross-protective efficacy induced by heat-adapted live attenuated nephropathogenic infectious bronchitis virus derived from a natural recombinant strain.
abstract: A natural recombinant nephropathogenic K40/09 strain of infectious bronchitis virus (IBV) was heat-adapted for possible future use as live attenuated vaccine. The K40/09 strain was selected during successive serial passages in specific-pathogen free (SPF) embryonated eggs at sub-optimal higher temperature (56°C). Unlike the parental strain, the attenuated strain, designated K40/09 HP50, was found to be safe in 1-day-old SPF chicks, which showed neither mortality nor signs of morbidity, and rarely induced ciliostasis or histological changes in the trachea and kidney after intraocular and fine-spray administration. K40/09 HP50 provided almost complete protection against two distinct subgroups of a nephropathogenic strain (KM91-like and QX-like subgroup) and elicited the production of high titers of neutralizing antibody (neutralization index of 3.6). We conclude that the K40/09 HP50 vaccine virus is rapidly attenuated by heat adaptation and exhibits the desired level of attenuation, immunogenicity, and protective efficacy required for a live attenuated vaccine. These results indicate that the K40/09 vaccine could be helpful for the reduction of economic losses caused by recently emergent nephropathogenic IBV infection in many countries.
authors.affiliation: Optipharm Inc., Osongsangmyung 6ro, Osong-eup, CheongJu, Chungcheongbuk-do, Republic of Korea.
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Lim
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Ha-Na
authors.initials: HN
authors.lastname: Youn
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Seong-Su
authors.initials: SS
authors.lastname: Yuk
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Jung-Hoon
authors.initials: JH
authors.lastname: Kwon
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Woo-Tack
authors.initials: WT
authors.lastname: Hong
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Gyeong-Bin
authors.initials: GB
authors.lastname: Gwon
authors.affiliation: Division of Vaccine Research, Korea National Institute of Health, Korea Centers for Disease Control and Prevention, Osong-eup, CheongJu 363-951, Chungcheongbuk-do, Republic of Korea.
authors.forename: Jung-Ah
authors.initials: JA
authors.lastname: Lee
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Joong-Bok
authors.initials: JB
authors.lastname: Lee
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea. Electronic address: songcs@konkuk.ac.kr.
authors.forename: Chang-Seon
authors.initials: CS
authors.lastname: Song
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D002645:Chickens; D018352:Coronavirus Infections / Q000517:prevention & control / Q000662:veterinary*; D006358:Hot Temperature; D001351:Infectious bronchitis virus / Q000276:immunology* / Q000302:isolation & purification; D007668:Kidney / Q000473:pathology; D011201:Poultry Diseases / Q000276:immunology / Q000517:prevention & control*; D012692:Serial Passage; D016019:Survival Analysis; D014132:Trachea / Q000473:pathology; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology / Q000302:isolation & purification; D014765:Viral Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D014613:Vaccines, Attenuated; D014765:Viral Vaccines
keywords: Attenuation; Cross-protective efficacy; Heat adaptation; Infectious bronchitis virus; Safety