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 of the Wisest" (1973), "World Population and Human Values: A New Reality" (1981), and "Anatomy of Reality: Merging of Intuition and Reason" (1983). Salk's last years were spent searching for a vaccine against HIV. His personal papers are stored at the University of California, San Diego Library. Salk was born in New York City on October 28, 1914. His parents, Daniel and Dora (née Press) Salk, were Ashkenazi Jewish; Daniel was born in New Jersey to eastern European immigrant parents, and Dora was born in Russia, immigrating when she was twelve. They had not received extensive formal education. He had