Kristen A. Feemster, MD, MPH, MSHP, is a pediatric infectious diseases physician and health policy researcher at the Children's Hospital of Philadelphia and the University of Pennsylvania Perelman School of Medicine. Her research focuses on the implementation of immunization recommendations, the epidemiology of vaccine-preventable diseases, and vaccine policy. She is Director of Research for the Vaccine Education Center and Medical Director of the Immunization Program at the Philadelphia Department of Public Health. Dr. Feemster has authored numerous peer-reviewed manuscripts and invited commentaries and regularly provides vaccine education to a wide range of audiences. She lives in Philadelphia with her husband and two children.