According to the World Health Organization (WHO), the yellow fever booster vaccination after the initial vaccination is not necessary. The Organization’s Strategic Advisory Group of Experts on immunization (SAGE) has reviewed the latest evidence and concluded that a single dose is sufficient to confer lifelong immunity against yellow fever disease.

With  600 million doses dispensed since the 1930s, only 12 known cases of yellow fever post-vaccination have been identified,  all of which occurred within five years of vaccination. This demonstrates that immunity does not decrease with time.

Yellow fever is an acute viral hemorrhagic disease transmitted by infected mosquitoes. The yellow fever virus causes varying degrees of disease, from mild symptoms to severe illness with bleeding and jaundice, and fatal outcomes. It is endemic to 44 countries in tropical areas of Africa and the Americas. Vaccination is considered to be the most important and effective measure against yellow fever. Protective immunity develops within 30 days for 99% of people receiving the vaccination.

For more information call (202) 974-3000 or visit the WHO’s website