Infectious bronchitis of chickens (IBC) is a highly contagious disease characterized by damage to the respiratory tract. Adult chickens exhibit respiratory symptoms, a 10-50% decrease in egg production, discoloration of the eggshell, deformation of the shell, and a deterioration in the marketability and breeding quality of eggs. The circulation of variant strains in poultry farms of the Russian Federation causes a significant decrease in egg production and the quality of the eggs obtained, causing significant economic damage to industrial poultry farming. The study aimed to presents materials and methods for the industrial and efficient use of live-vaccines against infectious bronchitis of hens from a variant strain. After the use of a live vaccine against infectious bronchitis of chickens from a variant strain, the development, live weight of chickens, and feed conversion during the rearing period were within the standard parameters. in present study, the safety for the growing period with a planned 97.6% was 98.8-98.9%. The uniformity of the herds when transferred to hen - hen was 94-95%. When carrying out immunoprophylaxis of IBS, local immunity is important, which can be ensured using a live spray vaccine - a method starting from the day old. When establishing circulation in the economy of variant strains of IBC virus, it is necessary to introduce vaccination against the variant strain into the scheme of treatment and preventive measures. The research results allow us to conclude that, for the effective prevention of chicken infectious bronchitis, immunization against IBS from variant strains should be introduced into the vaccine prevention scheme.
