Edward Jenner full-blown infection. Later, he injected Phipps with variolous material, the routine method of immunization at that time. No disease followed. The boy was later challenged with variolous material and again showed no sign of infection. Donald Hopkins has written, "Jenner's unique contribution was not that he inoculated a few persons with cowpox, but that he then proved [by subsequent challenges] that they were immune to smallpox. Moreover, he demonstrated that the protective cowpox pus could be effectively inoculated from person to person, not just directly from cattle. Jenner successfully tested his hypothesis on 23 additional subjects. Jenner continued his research
Caitlyn Jenner D. Weldon encouraged Jenner to switch to the decathlon. In 1970, Jenner placed fifth while debuting in the decathlon at the Drake Relays in Des Moines, Iowa. Jenner graduated from Graceland College in 1973 with a degree in physical education. At the 1972 U.S. Olympic trials in Eugene, Oregon, Jenner was in fifth place in the men's decathlon, behind Steve Gough and Andrew Pettes. Needing to make up a 19-second gap on Gough in the men's 1500 metres, Jenner qualified for the Olympic team by running a fast final lap, finishing 22 seconds ahead of the other runners. ( @25:58)