William C. Campbell, a retired scientist from Merck Research Laboratories, was jointly named the 2015 Nobel Prize winner in Physiology or Medicine with Satoshi Omura for the discovery of avermectin, which led to Merck's development of Mectizan (ivermectin), a treatment for river blindness (also known as onchocerciasis) in Africa, Latin America, and Yemen. They will share the prize with Youyou Tu for her discoveries concerning a novel therapy against malaria.

River blindness is a parasitic infection that can cause intense itching, skin discoloration, rashes, and eye disease that often leads to permanent blindness. It is spread by the bites of infected black flies that breed in rapidly flowing rivers in the affected countries. Established more than 25 years ago, the Mectizan Donation Program is a disease-specific drug donation program and public-private partnership. In 1998, Merck expanded the program to include the elimination of another disease, lymphatic filariasis. The program reaches more than 250 million people in the affected areas annually, with more than 2 billion treatments donated since 1987.

Source: Merck & Co. and Nobel Prize