The present invention provides the isolation and characterization of a new infectious bronchitis virus (IBV) variant, the IBV GA-13 variant, and the production of attenuated isolates thereof, including, but not limited to, the attenuated IBV GA13 isolate 103505 Kd E86, and the use of such IBV isolates in materials and methods for combating infectious bronchitis virus in poultry and reducing the economic impact that infectious bronchitis disease has on poultry production.