Dr. Daniel Salmon is a Professor in Global Disease Epidemiology and Control and the Director for the Institute for Vaccine Safety at Johns Hopkins Bloomberg School of Public Health. His primary research and practice interests are in optimizing the prevention of childhood infectious diseases through the use of vaccines. He has focused on post-licensure vaccine safety and the factors associated with parental decisions to vaccinate, or not vaccinate, their children. Dr. Salmon has conducted studies examining the rates of vaccine refusal, the reasons why parents refuse vaccines, the impact of healthcare providers and local and state policies on vaccine refusal and the individual and community risks of unvaccinated children. Other interests and research include the financing and delivery of vaccines, vaccine risk communication, and issues surrounding mandatory immunizations.