Yellow Fever Immunization Information and Clinic, Lanham, Maryland
Phone: 1-85570-SHOTS Yellow Fever Vaccination Clinic
Yellow Fever Vaccine Information

TripsEtc Travel & Vaccines Clinic, Lanham, MD

Phone: 1-85570-SHOTS

Get Yellow Fever Vaccination Information and Advice at

Yellow Fever Vaccine Information

TripsEtc Travel & Vaccines Clinic, Lanham, MD

Phone: 1-85570-SHOTS

Get Yellow Fever Vaccination Information and Advice at


A live attenuated vaccine against yellow fever was developed in 1936.

Vaccine efficacy — Protective immunity occurs in 90 percent of individuals within 10 days after receiving the 0.5 mL subcutaneous dose, and in nearly 100 percent of individuals within 3 to 4 weeks after vaccination. Immunity after a single dose is long-lasting. The international certificate of immunization is valid for 10 years; a booster 0.5 mL dose is required every 10 years for the certificate to be reissued.

Adverse effects — More than 550 million doses of vaccines have been administered since the 17D vaccine strain was developed. Serious adverse reactions to the 17D vaccine include two syndromes, known as yellow fever vaccine-associated neurotropic disease (YEL-AND) and yellow fever vaccine-associated viscerotropic disease (YEL-AVD), the risk is higher in elderly individuals.

Mild fever, headache, myalgia and malaise, and soreness at the site of inoculation can occur in the absence of liver function abnormalities. The vaccine is contraindicated for persons with known egg allergy. The yellow fever vaccine virus may be transmitted by transfusion of blood products. Vaccine recipients should defer blood product donation for two weeks.

YEL-AND — YEL-AND refers to yellow fever vaccine-associated neurotropic disease, an encephalitis caused by infection of the central nervous system with 17D virus. Onset occurs 2 to 8 days after vaccination; the event is nearly always self-limited. A few cases of Guillain-BarrĂ© and acute disseminated encephalomyelitis have also been described.

This complication has been observed in infants and adults. Cases in infants have diminished since restriction of vaccine administration to children older than nine months of age.

YEL-AVD — YEL-AVD refers to yellow fever vaccine-associated viscerotropic disease, a syndrome resembling wild-type yellow fever infection that occurs in the setting of yellow fever 17D vaccination. Onset of illness occurs 3 to 5 days after vaccination with fever, malaise, jaundice, oliguria, cardiovascular instability and hemorrhage.

This emphasizes the importance of careful assessment for vaccination need based on full understanding of disease epidemiology and travel itinerary, to avoid unnecessary risk of vaccine adverse effects but to ensure that patients with risk for exposure are protected.

Two acquired host factors appear to increase the risk of developing YEL-AVD after vaccination: advanced age and thymus disease.

Whom to vaccinate — In accordance with the Centers for Disease Control and Prevention (CDC), the United States Advisory Committee on Immunization Practices (ACIP), and the World Health Organization (WHO), we recommend vaccination for travelers to yellow fever endemic areas of Africa and South America, and for residents of those areas as adverse events (particularly in persons >60 years of age), the benefit of immunization should be established based on careful review of the traveler's itinerary with respect to potential for exposure to yellow fever virus. Individuals traveling in rural areas of countries within yellow fever endemic zones should be immunized even in the absence of official yellow fever reports, since active transmission may be under recognized.

Vaccination against yellow fever in endemic areas is performed as part of the Expanded Program of Immunization at nine months of age. In some African countries catch-up mass vaccination campaigns are undertaken based on assessments of geographic risk, as part of an initiative spear headed by the World health organization to increase vaccine coverage. Mass campaigns are also conducted in response to outbreaks in Africa and South America.

Certificates — In the United States the vaccine is distributed only through approved vaccinating centers.

Some countries in yellow fever endemic zones require an International Certificate of Vaccination as evidence of yellow fever immunization prior to entry; in addition, some countries outside of yellow fever zones also require evidence of immunizations prior to entry for individuals with recent travel in endemic countries. The international certificate of immunization is valid for 10 years; a booster 0.5 mL dose is required every 10 years for the certificate to be reissued.

Individuals with allergy to egg proteins may receive a waiver letter from a physician for travel to areas where the risk of disease is low but vaccination is an international travel requirement.

Pregnancy and breast feeding — Yellow fever 17D vaccine is contraindicated for use in pregnant women. Administration of yellow fever vaccine to breast-feeding women should be avoided except in situations where exposure to yellow fever viruses cannot be avoided or postponed. Yellow fever vaccine virus can be transmitted via breast-feeding.

Immunocompromised individuals — Yellow fever 17D vaccine should not be administered to immunocompromised individuals because of theoretical concerns about live attenuated virus vaccines.

Contraindications include inherited immune deficiency, lymphoma, leukemia, HIV/AIDS with low CD4 counts, immunosuppressive chemotherapy or radiotherapy, thymus disorders, DiGeorge's syndrome, and a history of thymectomy. Travelers with asymptomatic HIV infection may be immunized if potential exposure warrants; such patients should be advised of the possible risks of vaccination. Waiver letters can also be obtained for these patients.

Immune globulin — There is no specific yellow fever immune globulin product available. Immune globulin produced in the United States (where many military personnel have been vaccinated) frequently contains adequate titers of yellow fever neutralizing antibodies (typically 1:320). Passive immunization has been used off label to protect persons traveling to high-risk areas who have contraindications to vaccination.