The development of countermeasures to support an effective response to Transboundary Animal Diseases (TAD) poses a challenge on a global scale and necessitates the coordinated involvement of scientists from government, industry and academia, as well as regulatory entities. The Agricultural Defense Branch under the Chemical and Biological Defense Division (CBD) of the Department of Homeland Security (DHS), Science and Technology Directorate (S&T) supports this important mission within the United States. This article provides an overview of the Agricultural Defense Branch's vaccine and diagnostic TAD project.