Yellow Fever Prevention
Avoid Mosquito Bites
- Use Insect Repellent.On exposed skin when you go outdoors, use an EPA-registered insect repellent such as those with DEET, picaridin or oil of lemon eucalyptus. Even a short time outdoors can be long enough to get a mosquito bite. For details on when and how to apply repellent, see Insect Repellent Use and Safety in our Questions and Answers pages. See also Using Insect Repellent Safely from the EPA.
- Wear Proper Clothing to Reduce Mosquito Bites. When weather permits, wear long-sleeves, long pants and socks when outdoors. Mosquitoes may bite through thin clothing, so spraying clothes with repellent containing permethrin or another EPA-registered repellent will give extra protection. Don't apply repellents containing permethrin directly to skin.
- Be Aware of Peak Mosquito Hours. The peak biting times for many mosquito species is dusk to dawn, however Aedes aegypti, the main vector of Yellow Fever virus, feeds during the daytime. Take extra care to use repellent and protective clothing during daytime as well as evening and early morning or consider avoiding outdoor activities during these times when in areas where Yellow Fever is a risk.
Obtain Vaccine if Recommended
Yellow fever vaccine is a live virus vaccine which has been used for several decades. A single dose confers immunity lasting 10 years or more. If a person is at continued risk of yellow fever infection, a booster dose is needed every 10 years. Adults and children over 9 months can take this vaccine.
This vaccine is only administered at designated yellow fever vaccination centers; the locations of which can usually be provided by your local health department. Information regarding registered yellow fever vaccination sites can be viewed at the CDC Travelers' Health Yellow Fever website. For more information, see the 2002 Advisory Committee on Immunization Practice (ACIP) recommendations.
- Who Should Receive Yellow Fever Vaccine. Persons aged ≥ 9 months who are traveling to or living in areas of South America and Africa where yellow fever infection is officially reported should be vaccinated. While yellow fever is a very rare cause of illness in travelers, many countries have regulations and requirements for yellow fever vaccination that must be met prior to entering the country. Yellow fever vaccination requirements and recommendations for specific countries are available from the CDC Travelers' Health page.
Laboratory personnel who might be exposed to virulent yellow fever virus or to concentrated preparations of the 17D vaccine strain by direct or indirect contact or by aerosols should also be vaccinated.
- Who Should Not Receive Yellow Fever Vaccine. Yellow fever vaccine generally has few side effects; fewer than 20% of vaccinees develop mild headache, muscle pain, or other minor symptoms 5 to 10 days after vaccination. Severe reactions to the vaccine have been reported but are extremely rare. There are four groups of people who should not receive the vaccine unless the risk of yellow fever disease exceeds the risk associated with the vaccine.
- Yellow fever vaccine should never be given to infants under 6 months of age. In most cases, vaccination should be deferred until the child is at least 9 months of age.
- Yellow fever vaccine is not recommended for pregnant women.
- Persons who are allergic to eggs should not receive the vaccine because it is prepared in eggs. Notify your doctor prior to vaccination if you think that you may be allergic to the vaccine or to egg products.
- Persons with an immunosuppressed condition associated with AIDS or HIV infection, or those whose immune system has been altered by diseases such as leukemia and lymphoma, or by drugs and radiation should not receive the vaccine. People with asymptomatic HIV infection may be vaccinated if exposure to yellow fever cannot be avoided. Persons who have had thymus disease or thymus removal should not be vaccinated.
- Yellow fever vaccine should never be given to infants under 6 months of age. In most cases, vaccination should be deferred until the child is at least 9 months of age.
If you have one of these conditions, your doctor will be able to help you decide whether you should be vaccinated, delay your travel, or obtain a waiver. The physician should help you weigh the risks of exposure and contracting the disease against the risks of immunization, and consider alternative means of protection.
- Medical Waivers. Most countries will accept a medical waiver for persons with a medical reason for not receiving the vaccination. It may be useful to obtain written waivers from foreign country consular or embassy officials before departure. Travelers should contact the appropriate embassy or consulate for specific advice. Typically, a physician's letter stating the reason for withholding the vaccination and written on letterhead stationery is required by the embassy or consulate to issue a waiver. The letter should bear the stamp used by a health department or official immunization center to validate the International Certificate of Vaccination.
Content Source:
Division of Vector Borne Infectious Diseases
National Center for Zoonotic, Vector-Borne, and Enteric Diseases