Victoria Ruiz (left), a postdoctoral fellow in immunology, works with Brianna Delgado, a high school student that she mentors, at the Blaser Lab, inside NYU's Langone Medical Center in New York, NY.
Ramsay de Give for NPR
Tom Murphy, 56, in his home in Gainesville, Va., was diagnosed with ALS four years ago. An experimental drug seems to have slowed the progression of his disease, he says, though most ALS patients aren't as lucky.
T.J. Kirkpatrick for NPR
A health worker cleans his hands with chlorinated water before entering an Ebola screening tent at the Kenema Government Hospital in Sierra Leone. More than 300 Sierra Leoneans have died of the disease.