Evidence for Antibody Dependent Enhancement for an Avian Coronavirus

Avian infectious bronchitis (IB) is caused by a gamma coronavirus and is a highly infectious disease of chickens that is problematic for commercial chicken producers around the world.A major problem for managing this disease is the ability of the infectious bronchitis virus (IBV) to mutate and generate new variants and serotypes that yield current vaccines less protective.Numerous new serotypes and variants have emerged that are unique to geographical regions around the globe.Antibody dependent enhancement (ADE) is a phenomenon in which either non-neutralizing antibodies, or suboptimal (i.e., low) levels of neutralizing antibodies, facilitate entry into cells and promote increased viral replication.In this short communication, we report preliminary in vitro evidence of ADE using a chicken egg embryo model and a vaccine strain of IBV.To our knowledge, ADE has neither been reported nor explored for any viral disease of birds.