Studies on avian infectious bronchitis virus in New Zealand. 3. Efficacy of an attenuated live infectious bronchitis vaccine of New Zealand origin in broiler birds

Authors: Owen DJ, McCausland IP, Lohr JE
Publication: New Zealand Veterinary Journal, Volume 25, Issue 3, pp 53-55, Mar 1977
Publisher: Taylor and Francis

Animal type: Avian, Poultry, Production animal
Subject Terms: Animal remedies/veterinary medicines, Immune system/immunology, Viral, Respiratory system, Disease/defect, Infectious disease, Vaccination
Article class: Scientific Article

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Abstract: In a field trial the efficacy of a New Zealand Infectious Bronchitis (IB) vaccine in the forty-seventh egg passage was evaluated. The vaccine, administered via the drinking water, had only a very mild residual pathogenicity for IB susceptible and Mycoplasma gallisepticum-free birds. Immunity was challenged three weeks after vaccination by intratracheal inoculation with four different New Zealand types of IB virus. All groups of vaccinated chickens showed much less severe clinical and histological signs of respiratory disease than control chickens, and challenge virus was re-isolated from a lower number of the vaccinated birds. These results indicate that the vaccine effectively immunized the birds against all four challenge viruses.

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