1 Heidi J. Larson is a professor of Anthropology, Risk, and Decision Science in the Department of Epidemiology and Population Health and director of The Vaccine Confidence Project, London School of Hygiene and Tropical Medicine, London, UK. heidi.larson@lshtm.ac.uk.
2 William S. Schulz is a Ph.D. student in the Department of Politics, Princeton University, and an affiliated researcher at the Vaccine Confidence Project, London School of Hygiene and Tropical Medicine, London, UK. wschulz@princeton.edu.