The yellow fever vaccine is a live, single-dose vaccine that protects you against yellow fever, a mosquito-borne viral disease of tropical Africa and South America. For a medical elective in Zanzibar, Sri Lanka, Nepal or Bali, it is usually not needed: none of the four has yellow fever, and each asks for a yellow fever certificate only if you arrive from, or (for most of them) transit through, a country with yellow fever risk. Your flight route decides it.
Researched and editorially reviewed by Nils-Andre Stritt, travel4med. The medical content was reviewed by MUDr. Amandeep Grewal, a doctor on the travel4med team.
The yellow fever vaccine is a live attenuated vaccine against the yellow fever virus, which day-biting mosquitoes spread in parts of Africa and Latin America. The WHO says a single dose gives lifelong immunity with no booster needed, and that immunity develops in 80 to 100% of people within 10 days. The proof is an international certificate.
That certificate is the International Certificate of Vaccination or Prophylaxis, often shortened to ICVP or called the "yellow card". Under the International Health Regulations, the WHO says, countries may require it from travellers. That's why yellow fever sits in a different box from your other travel jabs: it can be a border document, not only a health choice.
How big is the disease itself? The WHO fact sheet of 20 October 2025 estimates 67,000 to 173,000 severe infections and 31,000 to 82,000 deaths each year in Africa and the Americas. It classes 27 African and 13 Latin American countries as high risk for yellow fever outbreaks. A safe vaccine exists, so prevention is the whole game.
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Usually not, if you fly to your placement directly from a country without yellow fever risk. The CDC country pages for Tanzania, Sri Lanka, Nepal and Indonesia all say the vaccine is not required for direct travel from the United States, and the CDC does not recommend it for travel to any of the four. The rule changes when your journey starts in, or stops over in, a risk country.
Think of it this way. Zanzibar, Galle, Pokhara and Bangli don't have yellow fever, and the four countries want to keep it that way. So they check travellers who come from places where the virus circulates. Your job is to know whether your route puts you in that group.
Three situations make the yellow fever vaccine a real question for you:
There's a medical side too. If your trip includes time in an area where the CDC recommends the vaccine, such as most of Kenya outside Nairobi, the former North Eastern Province and most of the former Coast Province, the yellow fever vaccine protects you there, not only at the next border.
All four ask for a certificate only from travellers who arrive from a country with yellow fever risk. The age threshold differs: 1 year and older for Tanzania, which includes Zanzibar, and 9 months and older for Sri Lanka, Nepal and Indonesia. For Bali, the CDC Indonesia page does not mention airport transits.
Here is what each source says, read on 3 November 2026:
| Destination | CDC entry rule | Counts long layovers? | CDC advice on the vaccine itself | Our destination page |
|---|---|---|---|---|
| Zanzibar (Tanzania) | Certificate required from age 1 if arriving from a risk country | Yes, transits of more than 12 hours | Generally not recommended | Not listed under vaccinations |
| Galle, Sri Lanka | Certificate required from 9 months if arriving from a risk country | Yes, transits of more than 12 hours | Not recommended | Not listed under vaccinations |
| Pokhara, Nepal | Certificate required from 9 months if arriving from a risk country | Yes, transits of more than 12 hours | Not recommended | Not listed under vaccinations |
| Bangli, Bali (Indonesia) | Certificate required from 9 months if arriving from a risk country | Not mentioned on the page | Not recommended | Not listed under vaccinations |
So what does our Zanzibar page ask for instead? Its vaccination answer lists hepatitis A, hepatitis B, measles, mumps and rubella, tetanus, diphtheria, polio and pertussis as required for taking part, rabies prophylaxis, typhoid and dengue as recommended but optional, plus malaria prophylaxis. Yellow fever only enters the picture through your route. Our Zanzibar placement guide and the nursing placement in Zanzibar cover the rest of the preparation.
For the full list of jabs across all four countries, start with our guide to vaccinations for a medical elective abroad. If you're studying in Switzerland and read German, travel4med.ch has a separate guide to the yellow fever vaccine before a placement in Zanzibar, written for Swiss students.
Because the certificate rule follows where you have been, not your passport. If your flight to Zanzibar connects in Nairobi or Addis Ababa, note that the CDC treats Kenya and Ethiopia as countries with yellow fever risk: it recommends the vaccine for most travellers to both. A short connection is not the problem. A layover of more than 12 hours is the trigger for Tanzania.
Look at your booking with the transit rule in mind:
Sound complicated? It rarely is in practice. The WHO places the high-risk countries in Africa and Latin America, so a route from Europe, North America or Asia via the Gulf does not trigger the rule. It's the students who live in, or travel through, risk countries in Africa or South America who need to plan the yellow fever vaccine early.
At least 10 days before you travel, says the NHS, so the vaccine has time to work. Book it with your other travel jabs 6 to 8 weeks before departure, because in the UK, for example, the NHS says only registered yellow fever vaccination centres give it. One dose then lasts for life for most people.
The certificate rules changed in your favour. TravelHealthPro, the UK's national travel health service, explains that the WHO extended the validity of the certificate from 10 years to the life of the person vaccinated, from 11 July 2016, and that this applies to certificates already issued. The NHS says the same: older cards with an expiry date are still valid. TravelHealthPro also quotes the WHO that boosters or revaccination cannot be required.
What about cost? In the UK, the NHS says the yellow fever vaccine is not free and typically costs around 60 to 85 pounds. Prices in your own country will differ, and some medical schools or insurers help with travel vaccines for placements. Our guide to medical elective insurance shows what a travel policy covers.
Combine visits where you can. Your clinic can plan the typhoid vaccine, the hepatitis B vaccine and, for Asia, the Japanese encephalitis vaccine at the same time.
Request all the important info for free, no obligation.
Because it is a live vaccine, some people should not have it. The NHS lists babies under 6 months, people with a weakened immune system, people allergic to the vaccine's ingredients including egg, anyone who reacted badly to a previous dose, people with a thymus disorder or whose thymus was removed, and people over 60 travelling where it is not generally recommended.
What if that's you and your route needs a certificate? TravelHealthPro says a Medical Letter of Exemption can be provided when a health professional advises that you should not be vaccinated on medical grounds. The WHO fact sheet confirms that medical exemptions must be certified. Carry the letter with your passport and tell your travel clinic your full route.
Side effects are usually mild. The NHS names headache, muscle pain, a raised temperature and soreness where the injection was given, which usually pass within 2 weeks. Rare serious reactions include allergic reactions and, very rarely, problems affecting the brain or organs. That's one more reason the yellow fever vaccine is given after a proper risk check, not "just in case".
Pregnant? The WHO says pregnant women should generally not be vaccinated, except during outbreaks. Discuss your route and timing with your doctor before you book flights.
Work through these as soon as your placement dates and flights are fixed:
Bite avoidance, because the yellow fever vaccine covers only one virus. On Zanzibar, malaria is the bigger issue: our Zanzibar page lists malaria prophylaxis, prescribed by your own doctor or a travel medicine service. Dengue occurs at our destinations too, and our pages say a dengue vaccination is only advisable after a previous dengue infection.
So the basics stay the same everywhere: repellent on exposed skin, long sleeves in the evening, and a net if your room is not screened. Our guide to malaria prophylaxis for a medical elective explains the options, and travel4med.at has an Austrian guide to malaria prophylaxis before a placement abroad in German. For the wider support network around your studies, see the futuredoctor.group ecosystem.
Planning a placement in Zanzibar, Sri Lanka, Nepal or Bali? We place medical, nursing and physician assistant students in all four destinations for clinical electives, final-year placements, nursing placements and observerships, and we go through your vaccination status with you during preparation. Book a free consultation, compare our destinations or read about our clinical placements abroad.
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