Rapid development of attenuated IBV vaccine candidates through a versatile backbone applicable to variants

Yuanlu Lu; Yiran Zeng; Haowei Luo; Na Chen; Lingcai Zhao; Haitao Zhang; Jun Xia; Jihui Ping

doi:10.1038/s41541-025-01114-z

Rapid development of attenuated IBV vaccine candidates through a versatile backbone applicable to variants

NPJ Vaccines. 2025 Mar 28;10(1):60. doi: 10.1038/s41541-025-01114-z.

Authors

Yuanlu Lu¹, Yiran Zeng¹, Haowei Luo¹, Na Chen¹, Lingcai Zhao¹, Haitao Zhang², Jun Xia³, Jihui Ping⁴

Affiliations

¹ MOE Joint International Research Laboratory of Animal Health and Food Safety, Engineering Laboratory of Animal Immunity of Jiangsu Province, College of Veterinary Medicine, Nanjing Agricultural University, 210095, Nanjing, China.
² Biotechnology Research Laboratory, Jiangsu Lihua Animal Husbandry Co., Ltd, 213168, Changzhou, China.
³ Xinjiang Academy of Animal Sciences Institute of Veterinary Medicine, Key Laboratory for Prevention and Control of Herbivorous Animal Diseases of the Ministry of Agriculture and Rural Affairs & Xinjiang Animal Disease Research Key Laboratory, 830000, Urumchi, China.
⁴ MOE Joint International Research Laboratory of Animal Health and Food Safety, Engineering Laboratory of Animal Immunity of Jiangsu Province, College of Veterinary Medicine, Nanjing Agricultural University, 210095, Nanjing, China. jihui.ping@njau.edu.cn.

Abstract

The antigen variability of the infectious bronchitis virus (IBV) has hindered vaccine effectiveness and perpetuated its epidemic. We engineered a rapid attenuation method for IBV variants. The strategy involves creating the rH-CPDF7 backbone by recoding a segment of the H120 nonstructural protein (NSP) genome via codon pair deoptimization (CPD), facilitating S gene integration from IBV variants via transformation-associated recombination (TAR) cloning. These recombinant strains exhibited even lower pathogenicity, indicating the effectiveness of CPDF7 in reducing virulence. Importantly, the rH-CPDF7 backbone demonstrated versatility, being applicable to the development of attenuated strains for IBV variants, including the QX-type, TW-type, and GVI-type strains (different genotypes). In conclusion, our method allows for the rapid development of attenuated strains by integrating the S gene of IBV variants into the rH-CPDF7 backbone. These recombinant strains can elicit a strong immune response and provide effective protection against homologous challenges. This strategy is crucial for developing live-attenuated vaccines against emerging IBV strains.

Grants and funding

2023A02007/Xinjiang Uygur Autonomous Region Major Science and Technology Project-Xinjiang Animal Disease Prevention and Control System Quality Improvement Project (2023A02007) and "Tianchi Talent" Introduction Program.