title: Protection Induced in Broiler Chickens following Drinking-Water Delivery of Live Infectious Laryngotracheitis Vaccines against Subsequent Challenge with Recombinant Field Virus.
abstract: Infectious laryngotracheitis virus (ILTV) causes acute upper respiratory tract disease in chickens. Attenuated live ILTV vaccines are often used to help control disease, but these vaccines have well documented limitations, including retention of residual virulence, incomplete protection, transmission of vaccine virus to unvaccinated birds and reversion to high levels of virulence following bird-to-bird passage. Recently, two novel ILTV field strains (class 8 and 9 ILTV viruses) emerged in Australia due to natural recombination between two genotypically distinct commercial ILTV vaccines. These recombinant field strains became dominant field strains in important poultry producing areas. In Victoria, Australia, the recombinant class 9 virus largely displaced the previously predominant class 2 ILTV strain. The ability of ILTV vaccines to protect against challenge with the novel class 9 ILTV strain has not been studied. Here, the protection induced by direct (drinking-water) and indirect (contact) exposure to four different ILTV vaccines against challenge with class 9 ILTV in commercial broilers was studied. The vaccines significantly reduced, but did not prevent, challenge virus replication in vaccinated chickens. Only one vaccine significantly reduced the severity of tracheal pathology after direct drinking-water vaccination. The results indicate that the current vaccines can be used to help control class 9 ILTV, but also indicate that these vaccines have limitations that should be considered when designing and implementing disease control programs.
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Mesula G
authors.initials: MG
authors.lastname: Korsa
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Glenn F
authors.initials: GF
authors.lastname: Browning
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Mauricio J C
authors.initials: MJ
authors.lastname: Coppo
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Alistair R
authors.initials: AR
authors.lastname: Legione
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: James R
authors.initials: JR
authors.lastname: Gilkerson
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Amir H
authors.initials: AH
authors.lastname: Noormohammadi
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Paola K
authors.initials: PK
authors.lastname: Vaz
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia; College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea.
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Devlin
authors.affiliation: The Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Carol A
authors.initials: CA
authors.lastname: Hartley
mesh_terms: D000818:Animals; D002645:Chickens; D060766:Drinking Water; D006566:Herpesviridae Infections / Q000235:genetics / Q000276:immunology / Q000517:prevention & control* / Q000662:veterinary*; D001352:Herpesvirus 1, Gallid / Q000235:genetics / Q000276:immunology*; D011201:Poultry Diseases / Q000235:genetics / Q000276:immunology / Q000517:prevention & control*; D014611:Vaccination / Q000379:methods*; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*
chemical_list: D060766:Drinking Water; D014765:Viral Vaccines