Do I Need a Yellow Fever Vaccine?

Official certificate of vaccination for Yellow Fever

Travelers often visit a travel clinic because they are told that they need a Yellow Fever (YF) vaccine. Travel agents may find themselves caught in the middle, but the decision of whether or not to get the vaccine should be based on a careful risk analysis carried out during a pre-travel health consult.

The risk of acquiring yellow fever depends on many factors; location and season of travel, duration of stay, activities while traveling and local rate of virus transmission.

What is Yellow Fever anyway? It is an infectious, febrile disease caused by the yellow fever virus (YFV). It can present with flu-like symptoms or sometimes cause illness serious enough to result in hospitalization or death. There is no specific treatment for yellow fever except what we in medicine like to call “supportive measures”. Fortunately, there is a very effective vaccine available that can be used to prevent the disease.

YFV is transmitted to humans by the bite of the Aedes mosquito, and thus another important way to avoid the disease is to take proper insect bite precautions, including the use of insect repellent and protective clothing (see our blog on How to Prevent Mosquito Bites).

It is important to note that yellow fever is only found in two regions of the world, in sub-Saharan Africa and the tropical Amazon basin in South America. Current YF endemic countries and vaccine recommendations can be found on the CDC (Centers for Disease Control) or WHO (World Health Organization) websites. This information is constantly being updated as disease patterns change.

Under International Health Regulations, you could be required to show proof of yellow fever vaccination before you are allowed entry into some countries. Even transiting through a YF endemic country with a short airport layover could require you to have the vaccine. Thus, your specific travel itinerary becomes important. Some countries, such as South Africa are more diligent than others about enforcing these requirements. The vaccine can only be administered at a registered YF vaccination site and proof of vaccination is recorded on an official Certificate of Vaccination. The vaccine must be administered at least 10 days prior to travel and is now considered valid for life (note: updated recommendation as of 2016). The vaccine should not be administered to anyone under the age of 9 months.

Though it protects against YFV, the vaccine itself can cause mild to serious side effects. 10% – 30% of people receiving the vaccine report mild flu-like symptoms. The risk of serious or life threatening complications is low but increases after the age of 60 and even more after 70. It is a live vaccine and should not be given to anyone who is pregnant or immune compromised.

Which brings us back to risk analysis. Visit your travel health specialist, who will consider all of your risk factors and help you determine whether the yellow fever vaccine is required or recommended.

Be informed, travel safe and Go Explore.