DEVELOPMENT OF ADENOVIRUS VECTOR INFECTIOUS BRONCHITIS VACCINE IN CHICKENS

Abstract

Infectious bronchitis (IB) is common in poultry and difficult to control. Vaccination is currently considered the best way to prevent IB. The IB virus (IBV) isolated in Taiwan could be clustered into two groups, Taiwan Group I (TW-I or TW1) and Taiwan Group II (TW-II or TW2). An IBV strain 3575/08 was isolated from an IBV-vaccinated chicken farm. Through sequencing analysis, this strain was clustered into TW-I. However, through cross-neutralization test, we found that 3575/08 has a serological correlation with TW-I and TW-II, with relatedness (R) values of 14.20% and 10.24%, respectively. Moreover, its R-value with Massachusetts (H120) is 5.64%. The broad cross-reaction with other serotypes, strain 3575/08 might be a good candidate for vaccine preparation. Therefore, we developed a recombinant adenovirus vector IBV 3575/08 S1 subunit vaccine (rAdS1), which utilizes a recombinant adenovirus expression system to induce humoral protective immunity. This adenovirus vector IBV vaccine may aid in the field control of IB in the future.