In 1937, Max Theiler, working at the Rockefeller Foundation, developed a safe and highly efficacious vaccine for yellow fever that gives a ten-year or more immunity from the virus. For his work on the yellow fever vaccine, he received the 1951 Nobel Prize in Physiology or Medicine.
Yellow fever, known historically as yellow jack, or yellow plague is an acute viral disease. In most cases symptoms include fever, chills, loss of appetite, nausea, muscle pains particularly in the back, and headaches. Symptoms typically get better within five days. In some people within a day of improving the fever comes back, there is abdominal pain, and liver damage begins causing yellow skin. If this occurs there is also an increased risk of bleeding and kidney problems.
The disease is caused by the yellow fever virus and is spread by the bite of the female mosquito. It only infects humans, other primates and several species of mosquito. In cities it is primarily spread by mosquitoes of the Aedes aegypti species. The virus is an RNA virus of the genus Flavivirus. The disease may be difficult to tell apart from other illnesses, especially in the early stages. To confirm a suspected case blood sample testing with PCR is required. The yellow fever virus was the first human virus discovered.