Yellow fever evolved over 3,000 years ago, and has since been a constant threat to populations in Africa and South America. A vaccine was created in 1930, providing lifelong immunity. However, since the 1980’s vaccination programs have declines, while urbanisation has increased rapidly. With no treatment available, this virus is ever more likely to become an epidemic.

History of Virus:
In 1648, the first reliable records of a yellow fever outbreak in Yucatan and Guadeloupe, in South America were recorded, though the virus is believed to have evolved in Africa over 3 000 years ago. This was followed by outbreaks along the US east coast, and later afflicted ports of France, Britain and Spain. Yellow fever was bought to the Northern Hemisphere with the slave ships. Until the
During the 40’s, 17D was mass distributed in South America, while the French vaccine was dispersed among French controlled Africa. In 1950;s th range of the mosquito suddenly increased, with Panama suffering its first case of yellow fever in 43 years. The disease spread quickly through much of Cnetral America. As vaccination has dropped off, rates of infection continue to rise, as well as dispertion, In the 1980’s the diseas occurred in Ethiopia, where it had bever previously occurred, with 120 000 cases and 24 000 deaths in Nigeria alone. Survalience of the jungle showed that more monkey were infected as well. The french vaccine was finally abandoned, due to high rates of postvaccinal encephalitis (inflammation of the brain), and 17D became the standard for yellow fever vaccination worldwide. (source)

What is yellow Fever:
Yellow fever is a virus of the Flaviviridae family, meaning it is spread through arthropod vectors, and the genus Flavivirus. Its close relatives include dengue and West Nile Virus. These viruses are single stranded RNA, effective at replicating in the cytoplasm of a host cell.