November 15, 2013
US research advances understanding of vaccination against Arkansas infectious bronchitis
USPOULTRY and the USPOULTRY Foundation completed a funded research project at Auburn University on research that advances the understanding of vaccination against Arkansas-serotype infectious bronchitis virus (IBV).
The project is part of the Association''s comprehensive research program encompassing all phases of poultry and egg production and processing.
Led by F.W. van Ginkel, researchers studied the immune response to Arkansas infectious bronchitis virus (ARK IBV). Despite widespread vaccination, ARK IBV continues to sporadically cause disease in US broilers. The part of the IBV that the chicken''s immune system recognises and responds to by producing a protective immune response is called the S1 protein. This protein often changes slightly as the virus replicates in birds, resulting in small but important changes in the S1 protein. These small changes are thought to allow the virus to escape from the immune response of the chicken. Chickens produce two types of antibody in response to IBV vaccination, IgA which is secreted onto the mucosal surfaces of the eyes and upper respiratory tract (mucosal immunity), and IgG which circulates systemically in the bloodstream (humoral immunity).
In this research, several ARK S1 proteins with slight differences were used to immunise chickens. The genes for these S1 proteins were inserted into an adenovirus (Ad5) and the adenovirus, which expressed the S1 protein, was then used as the vaccine. The dynamics of the immune response to the different S1 proteins were studied.
This research helps explain the cause of apparent vaccine failures and may lead to improved vaccines in the future.
US Poultry & Egg Association, based in Tucker, Georgia, is the all-feather organisation representing the complete spectrum of today''s poultry industry, whose mission is to progressively serve member companies through research, education, communication, and technical assistance.