A collaborative research project funded by the Irish government aims to comprehensively study the host immune response to bovine TB (bTB) in cattle, with a focus on the potential role of nutrition and Vitamin D. The study, led by University College Dublin in partnership with Queen’s University Belfast and the AgriFood and Biosciences Institute, will investigate how circulating Vitamin D concentrations influence the immune response and disease outcome in farms with bTB relapses. The research could enhance strategies for bTB eradication and is a first step towards establishing an all-island immunology hub to address knowledge gaps and develop improved controls for livestock diseases.