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 of my first year of medical school, I received an opportunity to spend a year in research and teaching in biochemistry, which I did. And at the end of that year, I was told that I could, if I wished, switch and get a Ph.D. in biochemistry, but my preference was to stay with medicine. And, I believe that this is all linked to my original ambition, or desire, which was to be of some help to humankind, so to speak, in a larger sense than just on a one-to-one basis." Concerning his last year of medical school Salk says: