title: Comparison between dot-immunoblotting assay and clinical sign determination method for quantifying avian infectious bronchitis virus vaccine by titration in embryonated eggs.
abstract: A sensitive and specific method for measuring the vaccine titer of infectious bronchitis virus (IBV) is important to commercial manufacturers for improving vaccine quality. Typically, IBV is titrated in embryonated chicken eggs, and the infectivity of the virus dilutions is determined by assessing clinical signs in the embryos as evidence of viral propagation. In this study, we used a dot-immunoblotting assay (DIA) to measure the titers of IBV vaccines that originated from different pathogenic strains or attenuation methods in embryonated eggs, and we compared this assay to the currently used method, clinical sign evaluation. To compare the two methods, we used real-time reverse transcription-PCR, which had the lowest limit of detection for propagated IBV. As a clinical sign of infection, dwarfism of the embryo was quantified using the embryo: egg (EE) index. The DIA showed 9.41% higher sensitivity and 15.5% higher specificity than the clinical sign determination method. The DIA was particularly useful for measuring the titer of IBV vaccine that did not cause apparent stunting but propagated in embryonated chicken eggs such as a heat-adapted vaccine strain. The results of this study indicate that the DIA is a rapid, sensitive, reliable method for determining IBV vaccine titer in embryonated eggs at a relatively low cost.
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, 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 05029, 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 05029, Republic of Korea.
authors.forename: Jin-Yong
authors.initials: JY
authors.lastname: Noh
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, 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 05029, Republic of Korea.
authors.forename: Gyeong-Bin
authors.initials: GB
authors.lastname: Gwon
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea.
authors.forename: Jei-Hyun
authors.initials: JH
authors.lastname: Jeong
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea.
authors.forename: Sol
authors.initials: S
authors.lastname: Jeong
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea.
authors.forename: Ha-Na
authors.initials: HN
authors.lastname: Youn
authors.affiliation: Daesung Microbiological Lab, 293 Sam-dong, Uiwang-city, Kyunggi-do 16103, Republic of Korea.
authors.forename: Yong-Hwan
authors.initials: YH
authors.lastname: Heo
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, 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 05029, Republic of Korea.
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Park
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea.
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Choi
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 05029, Republic of Korea. Electronic address: songcs@konkuk.ac.kr.
authors.forename: Chang-Seon
authors.initials: CS
authors.lastname: Song
mesh_terms: D000818:Animals; D002642:Chick Embryo; D018352:Coronavirus Infections / Q000276:immunology / Q000517:prevention & control; D015151:Immunoblotting / Q000379:methods; D001351:Infectious bronchitis virus / Q000276:immunology*; D011201:Poultry Diseases / Q000276:immunology / Q000517:prevention & control; D014611:Vaccination; D064166:Vaccine Potency; D014765:Viral Vaccines / Q000592:standards*
chemical_list: D014765:Viral Vaccines
keywords: Dot-immunoblotting assay; Embryo clinical sign; Infectious bronchitis virus; Titration; Vaccine