Evaluation of serum response of RAZI H-120 infectious bronchitis virus vaccine compared to imported vaccine in broiler chickens

Infectious bronchitis is an avian acute and highly contagious disease that causes heavy economic losses in poultry industry. Inactivated and live attenuated vaccines containing different virus serotypes (e.g. H-120) are widely used to control the disease. These vaccines should be periodically evaluated in the vaccinated chickens. The purpose of this study was to evaluate the serum responses following administration of Razi infectious bronchitis virus (IBV) H-120 strain vaccine and compare them with the results of the same commercial imported vaccine. In this case, a farm of broiler chickens includes two poultry house was selected. The groups of chickens in each house were administrated with one of the imported or RAZI IBV vaccines. Twenty chickens per group were bleeded at 4, 10, 20, 30 and 40 days after vaccination. The induced serum responses against IBV were evaluated in vaccinated chickens by ELISA and serum neutralization (SN) tests. In this research, no significant differences were found in ELISA antibody titer between the two groups that vaccinated with Razi H-120 vaccine and similar imported vaccine (CEVA Company) in any of the blood transfusion episodes. The results of the serum neutralization test confirmed the ELISA data. The result of this study was showed that IBV H-120 Razi vaccine, like the same imported vaccine, has potency to induce immunity in broiler flocks.