Development and immunoprotection assessment of novel vaccines for avian infectious bronchitis virus
Benli Huang, Sheng Chen, Zhanxin Wang, Keyu Feng, Yutao Teng, Ruoying Li, Guanming Shao, Jiaqian Rao, Xinheng Zhang, Qingmei Xie
Abstract
Infectious bronchitis (IB), a highly contagious acute respiratory disease affecting avian species, poses significant challenges to poultry production. The causative agent, infectious bronchitis virus (IBV), exhibits a high mutation rate, leading to limited cross-protection by existing vaccines. This necessitates the development of novel vaccines. This study, based on preliminary investigations conducted by our research team, identified six potential strains (PYG QX1, ZQF QX2, FQH QX3, LYZ QX4, XXX QX5, and CSL strains) for vaccine development. Previous pathogenicity test and serum cross-neutralization experiments conducted in this study have demonstrated that the FQH QX3 strain exhibited the weakest pathogenicity and the broadest spectrum of serum neutralization, while the CSL strain showed the highest pathogenicity and was the most challenging to neutralize, posing the greatest difficulty in prevention and control. Subsequently, we constructed and rescued recombinant vaccine candidates, H120-FQH QX3, and H120-CSL, expressing the S1 and N proteins of the FQH QX3 and CSL strains, respectively. Immunization protection experiments indicated that the H120-CSL recombinant vaccine candidate exhibited the most effective immune protection, making it a promising candidate for further study and evaluation as a recombinant vaccine. The S1 and N genes of the CSL strain demonstrated strong immunogenicity, making them potential candidate antigen genes for future vaccine development. • The antisera of the existing vaccine strains had difficulty in neutralizing the CSL strain. • The FQH QX3 strain has a good broad spectrum of monospecific antisera to neutralize the antigen. • The S1 and N genes of the CSL strain demonstrated good antigenicity. • The CSL strain can be considered as a candidate strain for selecting antigenic genes for vector vaccine development.