Background of the antigen
Infectious bursal disease (IBD) is caused by infectious bursal disease virus (IBDV) an avian Birnavirus first described in the USA near the town of Gumboro Delaware and thus the disease is also known as Gumboro disease. There are 3 recognized pathogenic types of IBDV; classic virulent (cvIBDV), sub-clinical (scIBDV), and very virulent (vvIBDV). All three pathogenic types of IBDV cause immune suppression which leads to secondary infections and a failure to produce an immune response to vaccines. The cvIBDV typically cause a high morbidity and low mortality disease while the scIBDV cause very little morbidity and no mortality. The vvIBDV cause an acute disease in chickens characterized by high morbidity and high mortality.
