Eradicating river blindness.

I'm reading about William C. Campbell, "a master's and doctoral graduate of the University of Wisconsin-Madison, [who] was awarded a share of the 2015 Nobel Prize in Physiology or Medicine."

River blindness... has been nearly eradicated thanks to Campbell's discoveries and the work of the Carter Center, which, working with the drug manufacturer Merck, has distributed more than 225 million free doses of the drug....