A symposium organized jointly by members of the ASTMH and the Society for Tropical Veterinary Medicine and deals with the broad subject of One Health. The Symposium focuses on vaccines, considered the most cost effective means of disease prevention. The role of vaccines in preventing the spread of disease from animals to humans  will be explored. Speakers will address examples where vaccination in animal species (livestock, poultry and wildlife) for zoonotic disease agents is used or could be used in order to reduce the risk of human disease. Specific examples are drawn from important human diseases caused by viral, bacterial and parasitic agents of animals. Speakers will address the potential for additional impact on disease risk reduction for selected vaccine-preventable diseases as well as new opportunities for vaccine interventions.