Yellow fever Because of this sylvatic cycle, yellow fever cannot be eradicated except by eradicating the mosquitoes that serve as vectors. In Africa, a third infectious cycle known as "savannah cycle" or intermediate cycle, occurs between the jungle and urban cycles. Different mosquitoes of the genus "Aedes" are involved. In recent years, this has been the most common form of transmission of yellow fever in Africa. Concern exists about yellow fever spreading to southeast Asia, where its vector "A. aegypti" already occurs. After transmission from a mosquito, the viruses replicate in the lymph nodes and infect dendritic cells in particular. From there,
Yellow fever vaccine Foundation to improve the vaccine from the "Asibi" strain, discovered that a favorable chance mutation in the attenuated virus had produced a highly efficacious strain that was named 17D. After field trials in Brazil, over one million people were vaccinated by 1939, without severe complications. For his work on the yellow fever vaccine, Theiler received the 1951 Nobel Prize in Physiology or Medicine. Only the 17D vaccine remains in use today. The outbreak of yellow fever in Angola in January 2016 has raised concerns about whether the global supply of vaccine is adequate to meet the need during a large