Background: IBD is a highly infectious disease of chickens found in all latitudes, due to the very high IBDV resistance to environmental conditions and commonly used disinfectants. Methods: The study was conducted to evaluate 3 IBD vaccination protocols in broiler chickens, in terms of their effectiveness (clinical observations and production performance of the flock), estimation of serological baseline values (with the use of two different commercial ELISA kits), and the degree of progression of BF lesions (histopathological lesion score - HLS) after vaccination with: (I) single vaccination using intermediate plus vaccine; (II) double vaccination with intermediate vaccine; (III) double vaccination with intermediate plus vaccine. Results: Birds on farms vaccinated with protocol II were characterized by the lowest antibody titers in both ELISA tests, and the lowest average HLS. Highest IDEXX titers were obtained in birds vaccinated with protocol III, while in the BIOCHEK test the highest titers were obtained for birds vaccinated with protocol I. Protocols I and III were characterized by similar HLS. Birds vaccinated with protocols I and III had higher immune uniformity. Conclusions: The estimated serological baseline values and the degree of HLS presents a clear picture of differences between different vaccination protocols and allows their adaptation for different farms depending on the current IBD epidemiological situation.