Hilary Koprowski he is chair of the department of radiation oncology at Christiana Hospital in Delaware. While at Lederle Laboratories, Koprowski created the world's first polio vaccine, based on an orally administered attenuated polio virus. In researching a potential polio vaccine, he had focused on live viruses that were attenuated (rendered non-virulent) rather than on killed viruses (the latter became the basis for the injected vaccine subsequently developed by Jonas Salk). Koprowski viewed the live vaccine as more powerful, since it entered the intestinal tract directly and could provide lifelong immunity, whereas the Salk vaccine required booster shots. Also, administering a vaccine
Jonas Salk making money." That belongs "in the category of mink coats and Cadillacs—unnecessary", he said. In the years after Salk's discovery, many supporters, in particular the National Foundation, "helped him build his dream of a research complex for the investigation of biological phenomena 'from cell to society'." Called the Salk Institute for Biological Studies, it opened in 1963 in the San Diego neighborhood of La Jolla. Salk believed that the institution would help new and upcoming scientists along in their careers, as he said himself, "I thought how nice it would be if a place like this existed and I was