Animal health is of great importance, in agricultural, food security, general economic and public health terms. The diseases thatour lab investigates (e.g. tuberculosis, anaplasmosis, Johne's disease, leptospirosis, and porcine reproductive and respiratorysyndrome virus (PRRSV)) cause billions of dollars in losses to U.S. agricultural producers. In addition, tuberculosis,anaplasmosis, leptospirosis and Johne's disease are zoonotic diseases, in which animals can serve as reservoirs and vectors ofoften fatal disease for humans. For example, Mycobacterium tuberculosis and Mycobacterium bovis, the bacteria that causetuberculosis, infect one- third of the world's human population, and are responsible for 1.5 million human deaths worldwide peryear. While Mycobacterium bovis infection of livestock and humans has been nearly eliminated in the U.S. by decades of cullinginfected animals and pasteurizing milk, importation of infected livestock and dairy products from Mexico and infected deerreservoirs have resulted in cattle and human infection and deaths in the U.S. The rise in consumer demand for "raw"unpasteurized milk also increases the danger of a tuberculosis outbreak caused by Mycobacterium bovis. History has shownthat the best way to treat disease is to prevent it through vaccination, with the long-term goal of driving it into extinction.