Advances in Bluetongue Virus Antigenicity and Vaccine Strategies: Progress and Perspectives

Bluetongue (BT) is an infectious disease affecting domestic and wild ruminants caused by the Bluetongue virus (BTV). The development of safe and broad-spectrum vaccines represents the most effective approach for disease control. This review comprehensively elaborates recent advances in BTV research, including etiological characteristics, antigenic epitopes and immunity, inactivated vaccines (IVs), live attenuated vaccines (LAVs), virus-like particle vaccines (VLPs), viral vectored vaccines, subunit vaccines, disabled infectious single cycle (DISC) vaccines, and disabled infectious single animal (DISA) vaccines, providing valuable references for further investigations on BTV antigenic epitopes and vaccine development. Despite this progress, several critical limitations remain. Many next-generation vaccines improve safety and DIVA compatibility at the cost of reduced immunogenicity, and most novel platforms are evaluated mainly in mouse models with few field trials in natural target species. Moreover, owing to the serotype-specific nature of BTV, most vaccines still fail to provide broad-spectrum immunity. Future efforts should therefore prioritize target-species validation, conserved T-cell antigens such as NS1/NS2, and multivalent or chimeric vaccine design.