John Franklin Enders (1897-1985) was an American medical scientist and Nobel laureate. Enders had been called "The Father of Modern Vaccines." In 1954 Enders, Thomas Huckle Weller, and Frederick Chapman Robbins were awarded the Nobel Prize in Physiology or Medicine "for their discovery of the ability of poliomyelitis viruses to grow in cultures of various types of tissue". This work was the first to show that viruses could be grown and manipulated outside of the body. The technique was called the Enders-Weller-Robbins method and Jonas Salk used it to develop the polio vaccine in 1952. In 1960, Enders led a team testing a measles vaccine on 1,500 retarded children in New York City and another 4,000 children in Nigeria. By late 1961, the vaccine was proven to be completely effective. He lived to be 88 years old and died of natural causes.