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
Influenza vaccine sera (chiefly against what we now call "Hemophilus influenzae"—a name derived from the fact that it was originally considered the etiological agent—and several types of pneumococci). Only one therapeutic measure, transfusing blood from recovered patients to new victims, showed any hint of success." In 1931, viral growth in embryonated hens' eggs was reported by Ernest William Goodpasture and colleagues at Vanderbilt University. The work was extended to growth of influenza virus by several workers, including Thomas Francis, Jonas Salk, Wilson Smith and Macfarlane Burnet, leading to the first experimental influenza vaccines. In the 1940s, the US military developed the first