William Campbell, PhD, won a Nobel Prize in 2015 for helping to develop the antiparasitic drug ivermectin. Dr. Campbell described the process that resulted in the discovery of the drug for a standing room-only crowd on the Cornell campus Oct. 13.
Ivermectin was first shown to be effective against parasitic roundworms. There are more than 15,000 species, some of which primarily infect humans and others that more commonly infect different animals: Think hookworms (people), heartworm (dogs) and encysted small strongyles (horses).
Dr. Campbell decided to focus on natural solutions, acquiring and testing thousands of microbial cultures from around the world. It came down to one mouse with a heavy parasite load that disappeared when treated with a substance called avermectin. An improved version, called ivermectin, has greatly reduced parasitic infections in a range of animals for almost 40 years.
Ivermectin has also proved effective against parasites that infect humans with disease. In Africa, whole communities have abandoned their villages to avoid river blindness. Ivermectin proved a powerful and blessedly simple preventive. One dose, given in pill form once or twice a year, made it possible to call together all village residents and treat them as a community. “It changed the face of public health drug delivery,” said Dr. Campbell.
This article was originally published in online by the Cornell University College of Veterinary Medicine.