To the acclaimed scientific memoirs of Ronald Ross1 and Santiago Ramón y Cajal2, both Nobel laureates in Physiology or Medicine, we can now add a third tome: William C. Campbell’s Catching the Worm. Campbell has the distinction of being Ireland’s only Nobel Prize winner for medicine. Catching the Worm takes us on a 90-year journey through the author’s richly fulfilling life, candidly revealing along the way his feelings and emotions regarding his parents, siblings, marriage and children, as well as his scientific career. The story begins in rural Ireland in the town of Ramelton, County Donegal. He was tutored at home until the age of thirteen, when he was sent off to a prestigious boarding school near Belfast. After graduation, Campbell attended Trinity College Dublin where he had the good fortune to study under noted parasitologist James Desmond Smyth, who was to have an enormous impact on the direction of Campbell’s future. In one of those interesting coincidences in history, Campbell’s physics teacher at Trinity was Ernest T. S. Walton, Ireland’s only other Nobel laureate in the sciences. A series of chance events led Campbell to pursue his doctorate in parasitology in the United States at the University of Wisconsin-Madison, and afterwards, to join Merck & Company, the pharmaceutical giant located in Rahway, New Jersey. Little did Campbell realize at the time that the latter decision would lead to a 33-year career and a Nobel Prize. “It has always been amazing to me,” Campbell writes, “how the really big decisions in life are brought about by chance.” The crux of the book is Campbell’s account of the discovery of the antiparasitic drug ivermectin, for which he was awarded the 2015 Nobel Prize in Physiology or Medicine. Alfred Nobel’s will states that the prize shall be given to those who “have conferred the greatest benefit on mankind.” Ivermectin, which paralyzes the larvae of the roundworm Onchocerca volvulus, the etiologic agent of river blindness in humans—the leading cause of blindness in the world—fits the bill. Due to ivermectin, river blindness is on the verge of being only the second human disease to be eradicated from Earth. The first was smallpox, in 1979. Campbell worried that his name might “be mud now” among his Merck colleagues, since so many of them had been part of the research project, but could not share the prize. His fears never materialized. In fact, quite the opposite was true. Merck organized a huge celebration in Campbell’s honor, and he was taken aback by the genuine warmth shown by all involved. The section detailing his Stockholm experience is an eye-opening trip into the fabulous world of Nobel ceremonies. Campbell’s speech at the Nobel Banquet on 10 December 2015—given here in full—is a must read. “Parasites are not generally regarded as being loveable,” Campbell spoke playfully. “It is so unfair! Unfair to the real parasites. . . . [I]t is time for parasites to get a little more respect!” Astonishingly, while working full time at Merck, Campbell somehow found time to teach parasitology to medical students at New York Medical College for twenty-five years. After retiring from Merck in 1990, he continued his love of teaching at Drew University’s Institute for Scientists Emeriti, where he mentored undergraduate students in original parasitological research, and taught a graduate course in the history of the biomedical sciences at the University’s Caspersen School of Graduate Studies. The author devotes only a single paragraph (pp. 142-3) in Catching the Worm to his interests in medical history, perhaps because he thinks of himself as an “amateur in the field.” I would have liked more detail, for, in reality, Campbell is an accomplished medical historian, having published numerous articles in the history of parasitology. His brilliant essay on the history of trichinosis in the Bulletin of the History of Medicine (1979) is the envy of many professional historians. It is also one of the reasons that the Medical History Society of New Jersey bestowed on Campbell its coveted David L. Cowen Award for Achievement in Medical History. Campbell’s wit and wisdom shine throughout the book. Many pharmaceutical scientists will appreciate Campbell’s comments decrying the industry’s abandonment of the empirical approach (screening compounds for activity) for the rational approach (designing compounds for activity) to drug discovery. This switch, Campbell contends, “has been to the detriment of global health. . . . The drugs to treat bacterial or parasitic diseases have virtually all come to us through development of empirical findings. If we ignore that history . . . that will be a self-inflicted tragedy.” Campbell sums up his long and productive life by echoing his father’s touching last words, “I have had a good innings.”3