Yellow fever is a serious viral infection transmitted by mosquitoes. It occurs mostly in Africa and South America. Although there is no specific treatment for yellow fever, most cases are mild, and those affected recover completely within a few days to a week. More severe cases may lead to serious bleeding, failure of the heart, liver, or kidneys, and death.

The yellow fever vaccine and proof of vaccination is currently required for travellers who plan to visit or transit certain countries in South America and Africa where the disease is active. In Canada, the vaccine is available only at certain travel medicine clinics designated as yellow fever centres.

If you are considering travel to an area where yellow fever occurs, the Public Health Agency of Canada (PHAC) strongly recommends a consultation with a travel medicine doctor beforehand to evaluate your risk and consider whether you need to be immunized for yellow fever. The U.S. Centers for Disease Control and Prevention (CDC) recommends that persons who are 9 months of age or older be immunized with the vaccine for yellow fever if they plan to travel to areas in South America or Africa where yellow fever has been officially reported.¹

Special considerations are made for certain groups, including:¹

• Pregnant women. In general, live-virus vaccines, such as yellow fever vaccine, should not be administered to pregnant women. Yellow fever vaccine is advised for pregnant women only when travel to an area where yellow fever has been officially reported is unavoidable and the woman is at an increased risk for exposure. If the yellow fever vaccine is given during pregnancy, the risk of damage to the fetus appears to be low.
• Nursing mothers. It is not known whether the yellow fever vaccine can be passed on to a breast-feeding infant. Vaccination is recommended for nursing mothers only when travel to an area where yellow fever has been officially reported is unavoidable.
• People with impaired immune systems. Most of these people should not be vaccinated for yellow fever. However, a choice whether to be immunized can be offered to people who are infected with human immunodeficiency virus (HIV), do not have symptoms, do not have AIDS, and have tests to verify immune system function.
• People with allergies or sensitivities to eggs. The yellow fever vaccine is produced in chick embryos, so the vaccine may harm those who have a severe allergy to eggs. People who are able to eat eggs or egg products can safely receive the vaccine.

For more detailed information, visit the Public Health Agency of Canada's Travel Health Web site at www.phac-aspc.gc.ca/tmp-pmv/index-eng.php.