H120 and 793/B type vaccine strains combination protects chickens against challenge with QX like Infectious bronchitis virus

Avian infectious bronchitis (IB) is a widely distributed poultry disease that has huge economic impact on poultry industry. The continuous emergence of new IBV genotypes and lack of cross protection among different IBV genotypes have been an important challenge. The present study was done to evaluate protection caused by two different serotypes’ vaccines (Massachusetts & 793/B) in order to evaluate protection against challenge with Iranian QX like-virus. The results showed a protective ability of the used vaccination program. The H120-793/B vaccinated group obtained 81% protection. These results indicate that the H120 793/B vaccines could be helpful for the reduction of economic losses caused by newly evolving QX IBV variants.