Wildlife vaccination strategies for eliminating bovine tuberculosis in white-tailed deer populations.

Many pathogens of humans and livestock also infect wildlife that can act as a reservoir and challenge disease control or elimination. Efficient and effective prioritization of research and management actions requires an understanding of the potential for new tools to improve elimination probability with feasible deployment strategies that can be implemented at scale. Wildlife vaccination is gaining interest as a tool for managing several wildlife diseases. To evaluate the effect of vaccinating white-tailed deer (Odocoileus virginianus), in combination with harvest, in reducing and eliminating bovine tuberculosis from deer populations in Michigan, we developed a mechanistic age-structured disease transmission model for bovine tuberculosis with integrated disease management. We evaluated the impact of pulse vaccination across a range of vaccine properties. Pulse vaccination was effective for reducing disease prevalence rapidly with even low (30%) to moderate (60%) vaccine coverage of the susceptible and exposed deer population and was further improved when combined with increased harvest. The impact of increased harvest depended on the relative strength of transmission modes, i.e., direct vs indirect transmission. Vaccine coverage and efficacy were the most important vaccine properties for reducing and eliminating disease from the local population. By fitting the model to the core endemic area of bovine tuberculosis in Michigan, USA, we identified feasible integrated management strategies involving vaccination and increased harvest that reduced disease prevalence in free-ranging deer. Few scenarios led to disease elimination due to the chronic nature of bovine tuberculosis. A long-term commitment to regular vaccination campaigns, and further research on increasing vaccines efficacy and uptake rate in free-ranging deer are important for disease management. Author summary: Many wildlife species act as reservoirs of bovine tuberculosis from which they can transmit to cattle and humans. In Michigan, bovine tuberculosis is endemic in white-tailed deer causing occasional spillovers to cattle. Here, with the help of a disease transmission model, we explored the use of wildlife vaccination in white-tailed deer to manage bovine tuberculosis in Michigan. We show that pulse vaccination effectively reduces disease prevalence, especially when combined with increased deer harvest. Key vaccine parameters for disease elimination are vaccine coverage and efficacy. While complete elimination is challenging, sustained vaccination and research to improve vaccine effectiveness are crucial for long-term disease management. Hence, this research informs integrated strategies to reduce bovine tuberculosis in deer populations. [ABSTRACT FROM AUTHOR]