William C. Campbell (scientist)

William Cecil Campbell (born 28 June 1930) is an Irish-born American biologist and parasitologist. He is known for his work in discovering a novel therapy against infections caused by roundworms. He won the 2015 Nobel Prize in Physiology or Medicine. He helped to discover a class of drugs called ivermectins. 
Campbell worked at the Merck Institute for Therapeutic Research and is currently a research fellow emeritus at Drew University.