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
Salk Institute for Biological Studies memorial to Jonas Salk, a golden engraving lies on the floor at the entrance to the institute: "Hope lies in dreams, in imagination and in the courage of those who dare to make dreams into reality." Francis Crick held the post of J.W. Kieckhefer Distinguished Research Professor at the Salk Institute. His later research centered on theoretical neurobiology and attempts to advance the scientific study of human consciousness. He remained in this post at the Salk Institute until his death in 2004. From 22–27 April 2010, the Salk Institute hosted glass sculptures by artist Dale Chihuly to celebrate 50 years