Do You Need a Yellow Fever Vaccine? What Travelers Need to Know

What is the difference between an entry requirement and a medical recommendation?

These are two distinct reasons to vaccinate, and they do not always overlap:

Entry requirement: Many countries in sub-Saharan Africa and South America require proof of yellow fever vaccination — the ICVP yellow card — if you are traveling from or through a country with yellow fever transmission risk. Without it, you may be denied entry or vaccinated at the border. This rule is traveler-origin-specific: it changes based on where you are flying from, not just where you are going.

Medical recommendation: Even when a country does not legally require the card, if yellow fever is endemic in the region you are visiting, public health authorities — including the CDC and WHO — may strongly recommend vaccination for your own protection 1Ref 1Centers for Disease Control and Prevention (2023).Yellow Fever — CDC Yellow Book 2024.Entry requirements vs. medical recommendations, yellow card requirements, vaccine effectiveness timeline, contraindications including live-virus warnings and age considerations.

A country may not require the card but still carry real disease risk, or may require the card from travelers arriving from certain countries but not others.

Which countries are affected?

Yellow fever is endemic in parts of sub-Saharan Africa and tropical South America 1Ref 1Centers for Disease Control and Prevention (2023).Yellow Fever — CDC Yellow Book 2024.Entry requirements vs. medical recommendations, yellow card requirements, vaccine effectiveness timeline, contraindications including live-virus warnings and age considerations. The exact list of countries with requirements or recommendations changes based on active outbreaks and is updated regularly by the WHO and CDC.

Rather than listing specific countries here — which can become outdated — the CDC Travelers' Health website (wwwnc.cdc.gov/travel) is the authoritative, up-to-date source. Enter your specific destination and all countries you will transit through to get current entry requirements and medical recommendations. A travel medicine clinician will do this lookup with you at your appointment 2Ref 2Centers for Disease Control and Prevention (2023).CDC Yellow Book 2024: Health Information for International Travel.General international travel medicine guidance; authoritative source for checking country-specific entry requirements and medical recommendations.

What is the yellow card, and where do you get it?

The International Certificate of Vaccination or Prophylaxis (ICVP) — informally called the yellow card — is the official document proving you have been vaccinated. It must be issued by an authorized yellow fever vaccination center, which may be a travel medicine clinic, certain public health departments, or a primary-care practice with authorization. Not every clinic or pharmacy can issue it.

The card must be signed and stamped correctly to be valid at border crossings. The vaccine takes about 10 days to become effective, so timing matters: you generally want vaccination complete at least 10 days before arrival in a risk area 1Ref 1Centers for Disease Control and Prevention (2023).Yellow Fever — CDC Yellow Book 2024.Entry requirements vs. medical recommendations, yellow card requirements, vaccine effectiveness timeline, contraindications including live-virus warnings and age considerations.

For most people, a single dose provides long-lasting — likely lifelong — protection, though there are specific medical exceptions. Your clinician will advise on whether a booster applies to your situation.

Who should be cautious about or avoid the yellow fever vaccine?

Yellow fever vaccine is a live-attenuated vaccine, meaning it contains a weakened live virus. This is why it cannot be given to everyone. Groups that require careful medical review before vaccination include 1Ref 1Centers for Disease Control and Prevention (2023).Yellow Fever — CDC Yellow Book 2024.Entry requirements vs. medical recommendations, yellow card requirements, vaccine effectiveness timeline, contraindications including live-virus warnings and age considerations:

• Infants under 9 months: generally not recommended due to risk of encephalitis.
• Pregnant women: generally avoided because it is a live virus. If travel to a high-risk area is unavoidable, risk-benefit must be weighed with an OB or travel medicine specialist.
• People with severe immunosuppression: from HIV, chemotherapy, organ transplant medications, or high-dose steroids. Live vaccines are generally contraindicated; a clinician can issue a medical waiver letter, though this may not be accepted at all borders.
• People with thymus disorders: associated with a rare but serious adverse reaction.
• Severe egg allergy: the vaccine contains egg protein.
• Adults aged 60 and older who have never been vaccinated: have a slightly higher risk of rare but serious adverse reactions and benefit from a direct risk-benefit discussion with a clinician.

This is why a formal travel medicine consultation — rather than a self-administered pharmacy visit — matters specifically for this vaccine.

What other vaccines might you need for the same trip?

A travel medicine appointment covers more than yellow fever. Depending on your destination, you may also need vaccines for hepatitis A 3Ref 3Nelson NP, Link-Gelles R, Hofmeister MG, Romero JR, Moore KL, Ward JW, Schillie SF (2018).Update: Recommendations of the Advisory Committee on Immunization Practices for Use of Hepatitis A Vaccine for Postexposure Prophylaxis and for Preexposure Prophylaxis for International Travel.Hepatitis A vaccine as part of a comprehensive travel vaccination plan for many destinations that overlap with yellow fever risk areas, typhoid, rabies, Japanese encephalitis, or meningitis, among others. Your routine vaccines should also be up to date before international travel 4Ref 4Centers for Disease Control and Prevention (2024).Routine Vaccines for Travel — CDC Travelers' Health.Ensuring routine vaccines are up to date before international travel, alongside destination-specific vaccines.

Bringing your full itinerary — including all transit countries, your departure date, and a list of current medications — to your travel medicine visit allows the clinician to build a complete vaccination and prevention plan.