Global Control of Infectious Bronchitis Requires Replacing Live Attenuated Vaccines by Alternative Technologies

Despite continuous and extensive efforts to control infectious bronchitis (IB) throughout the century, the disease continues to be one of the most economically relevant diseases affecting the poultry production worldwide. Since the early 1990s, numerous scientists have explicitly warned about the role of attenuated vaccines on IB virus (IBV) evolution and the detrimental consequences of their use to the poultry industry. Herein, we review evidence indicating that the use of live vaccines increases genetic/phenotypic diversity of IBV, enhances their fitness in the environment, and ultimately aggravates and perpetuates the problem for the poultry industry. The available evidence leads to the unequivocal conclusion that attenuated IBV vaccines should be replaced by vaccines using alternative technologies if IBV is to be controlled effectively.