title: Protection conferred by live infectious bronchitis vaccine viruses against variant Middle East IS/885/00-like and IS/1494/06-like isolates in commercial broiler chicks.
abstract: The ability of the infectious bronchitis H120 (a Massachusetts strain) and CR88 (a 793B strain) live attenuated vaccine viruses to protect from two Middle East infectious bronchitis virus isolates, IS/885/00-like (IS/885) and IS/1494/06-like (IS/1494) in broiler chicks was investigated. Day-old chicks were separated into three groups, (I) vaccinated with H120 at day-old followed by CR88 at 14 days-old, (II) vaccinated with H120 and CR88 simultaneously at day-old and again with CR88 at 14 days-old, (III) control unvaccinated. At 30 days-old, each of the groups was challenged with virulent IS/885 or IS/1494. Protection was evaluated based on the clinical signs, tracheal and kidney gross lesions and tracheal ciliostasis. Results showed that administering combined live H120 and CR88 vaccines simultaneously at day-old followed by CR88 vaccine at 14 days-old gave more than 80 per cent tracheal ciliary protection from both of the Middle East isolates. In addition, this programme conferred 100 per cent protection from clinical signs and tracheal or kidney lesions. The other vaccination programme, H120 at day-old followed by CR88 at 14 days-old, the tracheal ciliary protection conferred were 60 per cent and 80 per cent from IS/885/00-like and IS/1494/06-like, respectively.
authors.affiliation: University of Liverpool, Leahurst Campus , Neston, Cheshire , UK ; Faculty of Veterinary Medicine , University of Omar Al-Mukhtar , Al-Bayda , Libya.
authors.forename: Faez
authors.initials: F
authors.lastname: Awad
authors.affiliation: University of Liverpool, Leahurst Campus , Neston, Cheshire , UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Forrester
authors.affiliation: University of Liverpool, Leahurst Campus , Neston, Cheshire , UK ; NIHR Health Protection Research Unit in Emerging and Zoonotic Infections.
authors.forename: Matthew
authors.initials: M
authors.lastname: Baylis
authors.affiliation: Merial S.A.S. , Lyon cedex 07 , France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Lemiere
authors.affiliation: University of Liverpool, Leahurst Campus , Neston, Cheshire , UK.
authors.forename: Kannan
authors.initials: K
authors.lastname: Ganapathy
authors.affiliation: University of Liverpool, Leahurst Campus , Neston, Cheshire , UK.
authors.forename: Hussein Aly
authors.initials: HA
authors.lastname: Hussien
authors.affiliation: University of Liverpool, Leahurst Campus , Neston, Cheshire , UK.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Capua
keywords: Avian infectious bronchitis; Chickens; Health; Vaccines; Viruses