Cold War tensions and the polio vaccine polio vaccine. By the 1950, Jonas Salk had tested both live, attenuated polio vaccines and formaldehyde killed polio vaccines in monkeys and by 1952, began testing on humans. The killed vaccine was found to be effective, with proper filtration of the biological culture. A problem with this vaccine was the perception that to be adequately protected; a child had to get three Salk shots, properly spaced, and a recommended booster shot once a year, which was expensive. It should be noted however, that Jonas Salk, himself, has stated in interviews that this perception is not at all true. This 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