Helong Feng, Lun Yao, Zhe Zeng, Liren Jiang, Yu Shang, Hongcai Wang, Li Li, Zichen Wang, Xin Wang, Hongchun Yang, Qingqing Zhao, Xiangfei Ren, Tengfei Zhang, Rongrong Zhang, Yunqing Guo, Qin Lu, Qiao Hu, Wenting Zhang, Chan Ding, Huabin Shao, Guofu Cheng, Qingping Luo, Guoyuan Wen
In ovo vaccination is an attractive immunization approach for chickens. However, most live Newcastle disease virus (NDV) vaccine strains used safely after hatching are unsafe as in ovo vaccines due to their high pathogenicity for chicken embryos. The mechanism for viral pathogenicity in chicken embryos is poorly understood. Our previous studies reported that NDV strain TS09-C was a safe in ovo vaccine, and the F protein cleavage site (FCS) containing three basic amino acids (3B-FCS) was the crucial determinant of the attenuation of TS09-C in chicken embryos...
May 31, 2023: Journal of Virology