Vaccination is the most important way to control infectious bronchitis (IB) in chickens. Since the end of 2015. the Delmarva (DMV)/1639 strain of infectious bronchitis virus (IBV) has caused significant damage to the layer flocks in Eastern copyright. The efficacy of a combination of existing IB vaccines licensed in copyright was assessed against experimental challenge with this IBV s... https://www.campicon.com/