Sarah Stewart (cancer researcher) at the age of 39. Stewart returned to the NIH in 1951, joining the National Cancer Institute (NCI), and eventually becoming medical director. Stewart developed an interest in researching viral links to cancer in light of the pioneering research of Jonas Salk in developing a vaccine for the virus which caused polio. Stewart developed an interest in researching viral links to cancer in light of the pioneering research of Jonas Salk in developing a vaccine for the virus which caused polio. Stewart is credited with discovering the Polyomavirus in 1953. She and research partner, Dr. Bernice E. Eddy, were successful
Jonas Salk "I had an opportunity to spend time in elective periods in my last year in medical school, in a laboratory that was involved in studies on influenza. The influenza virus had just been discovered about a few years before that. And, I saw the opportunity at that time to test the question as to whether we could destroy the virus infectivity and still immunize. And so, by carefully designed experiments, we found it was possible to do so." In 1941, during his postgraduate work in virology, Salk chose a two-month elective to work in the laboratory of Thomas Francis at