ウシウイルス性下痢症ウイルスとワクチン防御戦略

Bovine viral diarrhea virus (BVDV) is a critical pathogen affecting the global cattle industry, causing severe economic losses primarily through persistent infection, immunosuppression, and reproductive failure. The virus exhibits substantial genetic diversity, with marked geographic variation in circulating subtypes, which complicates effective disease control. BVDV evades host immune responses by suppressing type I interferon signaling, impairing neutrophil function, and reprogramming host cellular metabolism, ultimately leading to the generation of persistently infected (PI) animals that serve as the principal reservoir for viral transmission. Current prevention and control strategies rely mainly on the identification and elimination of PI animals in combination with vaccination. However, conventional vaccines, including inactivated vaccines (IVs) and modified live vaccines (MLVs), have notable limitations, such as suboptimal subtype matching, interference by maternal antibodies, and safety concerns associated with MLV use in pregnant cattle. Emerging vaccine platforms, including mRNA vaccines, subunit vaccines, and multi-epitope vaccines, offer promising alternatives owing to their improved safety profiles, rapid design and production, and potential to elicit broad and robust immune responses. Future BVDV vaccine development should integrate artificial intelligence-driven design strategies with high-throughput sequencing and molecular epidemiological surveillance to enable the rational development of multivalent and multi-epitope vaccines. In addition, coordinated implementation of strain monitoring, PI animal clearance, and enhanced biosecurity practices will be essential for establishing a comprehensive and sustainable BVDV prevention and control framework.