In short: Yellow fever is a viral infection spread by mosquito bites in parts of sub-Saharan Africa, South and Central America and Trinidad. Most infections are mild, but a minority become severe, with jaundice, bleeding and organ failure, and many severe cases are fatal. A single dose of vaccine, given at a designated Yellow Fever Vaccination Centre at least 10 days before travel, gives lifelong protection for most people, and some countries require a certificate for entry.

This guide, written by a Ready Health prescribing pharmacist and based on UKHSA, NaTHNaC (TravelHealthPro) and NHS guidance, explains the risks, who should be vaccinated and how to get a certificate in the UK.

What is yellow fever?

Yellow fever is caused by a flavivirus passed on by infected mosquitoes, mainly Aedes species, which bite during the day. It cannot be caught directly from another person. The "yellow" refers to jaundice, which develops when the liver is badly affected.

Where is yellow fever a risk?

Risk areas are in tropical parts of:

sub-Saharan Africa (for example parts of West, Central and East Africa)
South and Central America (for example parts of Brazil, Colombia, Peru, Venezuela and Bolivia)
Trinidad in the Caribbean

Outbreaks continue to be reported. In 2025 and 2026, NaTHNaC highlighted cases in Colombia (mainly Tolima), Venezuela, Côte d'Ivoire and Ghana. Risk varies by region, season and activity, so always check the TravelHealthPro country page for your destination before you travel.

What are the symptoms of yellow fever?

Symptoms usually start 3 to 6 days after an infected bite. Many people have no symptoms or a short, flu-like illness:

fever and headache
muscle pain, particularly backache
nausea or vomiting
loss of appetite and tiredness

Most people recover within a few days. A small proportion enter a second, "toxic" phase shortly afterwards, with jaundice, abdominal pain, bleeding (from the gums, nose or stomach) and liver or kidney failure. Around half of people who reach this severe phase die. There is no specific antiviral treatment, so prevention matters.

If you feel unwell with a fever during or after travel to a risk area, seek medical advice promptly and mention your travel. Fever after travel to the tropics can also be malaria, which needs urgent testing.

How can I prevent yellow fever?

Vaccination where recommended or required for your trip.
Bite avoidance throughout the day and evening: an effective insect repellent such as one containing 50% DEET, long sleeves and trousers, and accommodation with screened windows or air conditioning.
Mosquito nets if sleeping in rooms that are not screened, and especially if malaria is also a risk.

How does the yellow fever vaccine work in the UK?

Question	Current UK position
Type of vaccine	Live attenuated vaccine, single injection
Usual minimum age	9 months (6–8 months only after specialist risk assessment)
Protection	Lifelong for most people after one dose
Certificate (ICVP)	Valid from 10 days after vaccination, for life
Where given	Only at designated Yellow Fever Vaccination Centres

Since July 2016, yellow fever certificates have been valid for the life of the person vaccinated, and countries should not ask for a booster for entry. A small group of people, such as those who were pregnant, had HIV or were very young when first vaccinated, or who have since had a stem cell transplant, may be advised to have a further dose if they remain at risk.

There have been temporary interruptions to UK vaccine supply (for example in summer 2025), so it is sensible to arrange vaccination well in advance.

Who should not have the yellow fever vaccine?

Because it is a live vaccine, it is not suitable for everyone. It is usually avoided in:

babies under 6 months
people with a weakened immune system from illness or treatment
people with a thymus disorder or who have had the thymus removed
anyone who has had a severe allergic reaction to a previous dose or a vaccine component

Extra caution and an individual risk assessment are needed for people aged 60 and over (who have a higher, though still rare, risk of serious side effects), pregnant or breastfeeding women, and people living with HIV. If vaccination is not appropriate but a certificate is required, the centre can consider issuing a medical exemption letter.

Where can I get the yellow fever vaccine near Wigan?

In England, Wales and Northern Ireland, yellow fever vaccine can only be given at clinics designated by NaTHNaC as Yellow Fever Vaccination Centres; in Scotland, centres are designated by Public Health Scotland. You can search for your nearest centre on the NaTHNaC website. Ready Health in Standish is not currently a designated centre, but we can help you plan your other travel vaccines and point you to a local centre.

Frequently asked questions

How long before travel should I have the yellow fever vaccine?

At least 10 days before arrival, because the certificate only becomes valid after 10 days. Ideally book several weeks ahead.

Do I need a yellow fever booster?

Most people do not. One dose is considered lifelong, but a few groups may be advised to have another dose if still at risk.

I have lost my yellow fever certificate. What should I do?

Contact the centre that vaccinated you, as they may be able to issue a replacement from their records.

Do I need a certificate if I am only transiting through a risk country?

Some countries require a certificate from travellers who have transited through a risk country, sometimes even for short airport stops. Check the entry requirements for each country on your route.

Key takeaways

Yellow fever is spread by day-biting mosquitoes in parts of Africa, South and Central America and Trinidad.
Severe disease is often fatal and there is no specific treatment.
One dose of vaccine gives lifelong protection for most people; the certificate is valid 10 days after vaccination.
The vaccine is only available from designated Yellow Fever Vaccination Centres.
Bite prevention remains important even if you are vaccinated.

Sources and further reading

Last reviewed: October 2026 by Shamir Patel, Independent Prescribing Pharmacist, Ready Health. This article is general information and does not replace advice from your own clinician.

Planning a trip to Africa or South America? Ready Health in Standish offers travel health consultations for people in Wigan, Chorley, Horwich and Bolton, covering vaccines, malaria prevention and bite avoidance for your itinerary. Book a travel health consultation or call 01257 676001.