Third-year medical student Allie Tetreault, left, talks with Gabrielle Nuki, 16, at Maine Medical Center in Portland, Maine. Gabrielle helps med students practice patient care.
Barbara Bush helps a nun to fit on a hearing device during a 2012 event in Gulu, Uganda. She says was interested in architecture as a college student but became a global health activist after visiting East Africa with her parents.
Dr. Tom Frieden, director of the CDC, talks with staff from Doctors Without Borders during a visit to the nonprofit group's newest Ebola treatment center in Monrovia, Liberia.
Tommy Trenchard for NPR