Dr. Salmon's training, research and practice interests are in epidemiology and health policy. He has focused on post-licensure vaccine safety and the factors associated with parental decisions to vaccinate, or not vaccinate, their children. Dr. Salmon served as the Director of Vaccine Safety at the National Vaccine Program Office, where he was responsible for coordinating federal vaccine safety activities. Dr. Salmon has conducted a broad range of studies examining the safety of vaccines, the rates of vaccine refusal, the reasons why parents refuse vaccines, the impact of health care providers and local and state policies on vaccine refusal and the individual and community risks of unvaccinated children. Dr. Salmon is widely published in the medical literature.