Immunological and genetic analysis of vaccine strains and regional variants of infectious bronchitis virus is examined.

Abstract

Abstract Infectious bronchitis virus (IBV) is an acute and highly contagious coronavirus characterized by respiratory and systemic pathology in chickens. Frequent genetic mutation in the spike (S) glycoprotein repeatedly induces regional variants. Although IBV vaccines are extensively utilized in chicken flocks, their efficacy is diminished by variant serotypes and poor cross-protection. To provide restored strategy for the IBV protection, we analyzed the genetic distance between local IBV variants and other coronaviruses, including SARS-CoV-2. We also compared the genetic sequence of the S1 glycoprotein in three commercial vaccine strains. Then, we examined immune responses by vaccine and regional strains in primary chicken embryonic kidney cells and splenocytes. Featured pathways for innate immunity and gene expressions for innate immune response was observed. Our study is expected to provide valid information for vaccine development against emerging variants. Supported by funding from the office of Research Support, Kangwon National University, a 2020 Research Grant from Kangwon National University (no. 520200065), and a National Research Foundation of Korean (NRF) grant funded by the Korea government (MSIT) (no. 2020R1G1A1099715)