Yellow fever


yellow-feverYellow fever is a viral disease, found in tropical regions of Africa and the Americas. The "yellow" in the name refers to the jaundice that affects some patients. It principally affects humans and monkeys, and is transmitted via the bite of Aedes mosquitoes. It can produce devastating outbreaks, which can be prevented and controlled by mass vaccination campaigns.

Large scale outbreaks occur every 3 to 10 years in villages or cities in the absence of large scale immunization. Sporadic cases can occur regularly in endemic areas.

The incubation period of the virus is 3 to 6 days after a bite from an infected mosquito. About 15% of infections progress to fever and jaundice. While only the minority of cases are severe, case fatality rate may be 25% to 50% among patients with syndrome of haemorrhage, jaundice, and renal disease.

Vaccination is the most important preventive measure against yellow fever. The vaccine is safe, affordable and highly effective. A single dose of yellow fever vaccine is sufficient to confer sustained immunity and life-long protection against yellow fever disease and a booster dose of yellow fever vaccine is not needed. The vaccine provides effective immunity within 30 days for 99% of persons vaccinated.

Yellow fever vaccine supply in an emergency 
yf-ghana  View yellow fever vaccine supply in an emergency [pdf 758 Kb]
Yellow fever strategic response framework 

YF-srfThe Strategic Response Framework guides the international response to the 2016 yellow fever outbreak in Angola, Democratic Republic of the Congo and Uganda, and supports other countries to prepare for the importation of cases.

View the yellow fever strategic response framework [pdf 1.32MB]

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Related links

Fact sheet on yellow fever

More on yellow fever