MOLECULAR INSIGHTS INTO INFECTIOUS BRONCHITIS VIRUS PATHOGENESIS, HOST IMMUNE RESPONSE, AND IMPLICATIONS FOR VACCINE DEVELOPMENT

Abstract

Infectious bronchitis virus (IBV) is a highly contagious avian coronavirus that continues to pose significant economic and biosecurity challenges to the poultry industry worldwide. IBV causes multisystemic infections in poultry affecting the reproductive, respiratory, and renal systems, leading to significant economic losses. The virus demonstrates great genetic variety due to high-frequency mutations and recombination, giving rise to a multitude of variants that complicates disease control efforts. The pathophysiology and clinical relevance of IBV are rooted in its host-specificity, structural characteristics, and immune-evasion pathways. The avian immune system stimulates humoral and cell-mediated immunity in response to a subsequent antigen exposure. In addition to adaptive responses, IBV infection initiates innate immunological responses involving heterophils, macrophages, dendritic cells, cytokines, and complement proteins. Despite the use of live-attenuated and inactivated vaccines, IBV outbreaks continue to occur globally underscoring the shortcomings of current immunisation approaches. The evolution of IBV has presented obstacles for vaccine development, which have been addressed via DNA-based, recombinant, subunit, and reverse genetic vaccines. To reduce the burden of IBV, creative vaccination techniques must be designed with a thorough understanding of IBV-host interactions. This review highlights the significance of a thorough understanding of IBV-host interactions and the creation of innovative vaccination techniques to counteract this changing disease by combining the most recent findings.