Reviewed by GPhC Pharmacist at Priory Pharmacy, York
Yellow fever is different from most travel vaccines. It comes with its own official paperwork. Because of this, people often focus only on the certificate. They forget to ask two other key questions:
- Am I actually at risk of catching yellow fever?
- What does the vaccine involve, medically?
Yellow fever is a serious disease. It can cause severe bleeding and can be deadly. The vaccine works very well. But it’s also the most complex vaccine used in travel medicine. A pharmacist needs to check each patient carefully before giving it.
What Is Yellow Fever?
Yellow fever is caused by a virus. It’s related to dengue and Zika.
How you catch it:
- Through the bite of an infected mosquito
- Found in tropical Africa and South America
- Spreads between monkeys and forest mosquitoes in rural areas
- Can also spread between people and mosquitoes in cities
What happens if you catch it:
- Most cases are mild, or cause no symptoms at all
- About 15 in 100 people get seriously ill
- Severe illness can cause high fever, yellowing skin (jaundice), bleeding, and organ failure
- There is no cure 20 to 50 in 100 severe cases end in death
- Around 200,000 people get sick and 30,000 people die from it each year, mostly in Africa
Do You Need the Vaccine?
There are two separate questions here. People often mix them up.
1. Entry rules
Some countries require a vaccination certificate before they let you in. This is called the “yellow fever card.”
- Rules differ by country
- Some countries ask everyone for it
- Others only ask travellers coming from at-risk countries
- Rules can change during disease outbreaks
- Check the NaTHNaC TravelHealthPro website for current rules
2. Your actual health risk
Even if a country doesn’t require the certificate, you might still be at risk. And even if it does require one, your real risk might be low.
Higher risk if you:
- Visit rural or forested areas
- Do outdoor activities with lots of mosquito exposure
- Travel during peak mosquito season
Lower risk if you:
- Stay in major cities with little to no yellow fever activity (e.g. Nairobi)
At Priory Pharmacy in York, we check both your real risk and the paperwork rules. This way, our advice is based on your health, not just the border rules.
About the Vaccine
The vaccine is called Stamaril. It’s a “live” vaccine. That means it contains a weakened, but still live, version of the virus.
Why this matters:
- Live vaccines give strong, long-lasting protection often after just one dose
- But they’re riskier for people with weak immune systems
Key facts:
- One dose protects over 99 in 100 healthy adults
- In 2013, the WHO confirmed one dose gives lifelong protection for most people
- You no longer need a booster every 10 years
- Your certificate is now valid for life in most cases
- Note: not everyone (including some border staff) knows about this update yet
Who Should NOT Have the Vaccine
Because it’s a live vaccine, some people should not receive it. This is why a proper check-up matters.
Cannot have the vaccine:
- Weak immune system includes HIV/AIDS with low CD4 count, people on immune-suppressing drugs, or with blood cancers
- Babies under 6 months too risky for their nervous system. Usually wait until 9 months old
- Severe egg allergy the vaccine is made using eggs. (Mild egg intolerance is fine)
- Thymus problems including thymus removal or DiGeorge syndrome
Needs extra care and discussion:
- Adults over 60 higher chance of side effects. Risk should be discussed first
- Pregnant or breastfeeding usually avoided, but may be considered if travel risk is high
If You Can’t Have the Vaccine
You can get a medical exemption letter instead, signed by a clinician at a certified vaccination centre.
Important: This letter does not guarantee entry. Each country’s border staff decides whether to accept it. Some countries may still require quarantine. Talk this through with your pharmacist before you travel.
This article gives general information only. It is not personal medical advice. Yellow fever vaccination is only given at approved centres, after a one-to-one health check. Priory Pharmacy in York is an approved centre book a travel consultation to find out what you need.
Frequently Asked Questions
The yellow fever vaccine is recommended for travellers visiting areas where yellow fever is present in parts of Africa and South America. Some countries also require proof of vaccination for entry.
A single dose of yellow fever vaccine is generally considered to provide lifelong protection for most people. However, some travellers may require additional advice depending on their health status and travel plans.
Most side effects are mild and may include soreness at the injection site, headache, muscle aches or a mild fever. Serious adverse reactions are rare but should be discussed with a travel health professional before vaccination.