Yellow Fever Vaccine
- Yellow Fever Vaccine
- Side Effects
- Vaccination > 60 Years of Age
- Medical Exemption Certificates
- Avoiding Travel to a Yellow Fever Risk Area
Yellow fever is a virus that is transmitted by infected mosquitoes. Avoiding mosquito bites is a very important part of protecting yourself from yellow fever. See the yellow fever page for further information.
The yellow fever vaccine protects against yellow fever. After you have received the vaccine you are given a yellow fever vaccine certificate to prove that you have received the vaccine and are protected from infection. This certificate is designed to fit inside your passport, and is valid for life.
The vaccine can be recommended for two reasons:
- To protect you from being infected when you travel to a country where yellow fever virus occurs. See individual country pages for specific information for your destination.
- To prevent the international spread of disease between countries. The countries that require proof of vaccination are those where either the disease occurs, or where it could occur because they have the correct mosquito and monkey species that could harbour the infection.
Proof of vaccination is most often required for travellers journeying from countries with yellow fever to countries where transmission could occur (and sometimes for travellers transiting through such countries).
Stamaril® is the yellow fever vaccine available in the UK, it is manufactured by Sanofi Pasteur and is made in chicken eggs. The vaccine can be given from 9 months of age, and may be given to infants from 6 months but only in special circumstances.
Stamaril® is a live vaccine, which means that it contains a weakened form of the yellow fever virus. Live vaccines do not cause disease in healthy people but are not suitable for people with an impaired immune system, for example, caused by drug treatment or underlying illness. This is because the weakened viruses can multiply and may cause a yellow fever like disease in these individuals.
One dose of vaccine provides lifelong protection in most people. A booster dose would only be recommended if you were previously vaccinated in one of the following circumstances:
- while pregnant
- less than two years old
- had a weakened immune system
Contraindications to vaccination
There are some people who cannot be given the yellow fever vaccine, these include:
- infants less than 6 months of age
- allergy to eggs, chicken proteins or to a previous dose of yellow fever vaccine
- history of thymus dysfunction and/or thymectomy, thymus disease e.g. myasthenia gravis, Di George syndrome
- a suppressed immune system due to disease
- immunosuppressant medication, such as chemotherapy drugs, methotrexate, azathioprine etc. or steroids
Vaccination should usually be avoided during pregnancy and when breastfeeding. A healthcare practitioner will discuss the risks and benefits of vaccination in these circumstances.
The vaccine can be given to those with HIV infection, but only if their CD4 counts are > 200 and they are stable on treatment.
Common Side effects
It is common to experience mild side effects after having the yellow fever vaccine such as:
- muscle pain
- mild fever
- soreness at the injection site
These side effects can occur from the day of vaccination up until 14 days after vaccination and usually last no more than 3 days.
Rare side effects
Rarely, serious complications occur after receiving the yellow fever vaccine. These are more common in those over 60 years of age. These include:
- Yellow fever vaccine associated neurological disease (YEL-AND) a condition affecting the brain and nervous system, causing symptoms such as confusion and problems with movement and co-ordination. The risk of YEL-AND is estimated as follows:
- over 60yrs = 2.2 per 100,000 doses of vaccine administered
- less than 60yrs = 0.8 per 100,000 doses of vaccine administered
- Yellow fever vaccine associated viscerotropic disease (YEL-AVD) similar to yellow fever itself with multi organ failure and death in more than 60% of cases. The risk of YEL-AVD is estimated as follows:
- over 60yrs = 1.2 per 100,000 doses of vaccine administered
- less than 60 yrs = 0.3 per 100,000 doses of vaccine administered
If you are aged > 60 you can receive the vaccine, but only if you are fit and well, understand the risks of vaccination and have a real risk of yellow fever virus at your destination (rather than requiring the vaccine just for certificate purposes). A healthcare practitioner will discuss your risk of disease at your destination and the potential risks of the vaccine, to enable you to make an informed decision regarding vaccination.
A healthcare practitioner will decline to vaccinate you if there is a contraindication to the vaccine and may decline to vaccinate if the risk of serious side effects is assessed as being higher than the disease risk. If the risk of disease is deemed low, and you agree, a medical exemption certificate can be issued in these circumstances. A medical exemption certificate is only valid for one trip. You must be reassessed on subsequent trips. You must practice strict mosquito bite avoidance during travel because you will not have any protection from the vaccine against potential infection.
If you have a contraindication to the vaccine or the risk of serious side effects is high, and there is a significant risk of contracting yellow fever on your trip you are likely to be advised to cancel or change your travel plans. Healthcare practitioners are not obliged to administer yellow fever vaccine, if they believe it unsafe to do so, or it is not required for your trip. If you have any medical problems it is best to seek travel advice before you book your trip.
If you have recently received the yellow fever vaccine and feel unwell please contact your GP or the 111 service if your GP practice is closed.
In a medical emergency, when someone is seriously ill and their life is at risk, dial 999.
Further information is also available on the NHS Inform website