William Campbell

Campbell's work led to ivermectin, a drug derived from avermectin, which became the primary weapon in the global effort to eliminate onchocerciasis, also known as river blindness. The disease, caused by a parasitic roundworm transmitted by blackflies, had blinded or visually impaired millions of people in sub-Saharan Africa, and ivermectin dramatically reduced its prevalence through mass drug administration programs.

Satoshi Omura isolated and cultured strains of the soil bacterium Streptomyces from environmental samples in Japan and sent cultures to William Campbell's team at Merck pharmaceutical company in the United States. Campbell screened those cultures and identified that they produced avermectin, which was then chemically modified into the more potent derivative ivermectin for clinical use.

Campbell shared the 2015 Nobel Prize in Physiology or Medicine with Satoshi Omura of Kitasato University in Japan and Tu Youyou of the China Academy of Chinese Medical Sciences. Omura was recognized for isolating the bacterial strains that produced avermectin, while Tu Youyou was honored separately for discovering artemisinin, a breakthrough antimalarial drug.

Campbell carried out his avermectin research at the Merck Institute for Therapeutic Research in New Jersey, where he worked as a parasitologist. He later joined the faculty at Drew University in Madison, New Jersey, after retiring from Merck.