Technical Abstract: Brucella abortus is an intracellular pathogen that causes reproductive losses in cattle and zoonotic infections in people. An eradication program based on serologic detection and vaccination has been in place for decades in the United States. Brucella use multiple molecular mechanisms to modify their environment in host cells and facilitate survival and replication. Immunologic protection against brucellosis is via cell-mediated immunity. Regulatory programs are the most cost-efficient way to control Brucella abortus and prevent human infection.