Arilvax (Yellow fever vaccine)

How does it work?

This vaccine contains a live, weakened form of the yellow fever virus. It provokes the body's immune response without causing the disease.When the body is exposed to foreign organisms, the immune system produces antibodies. These antibodies are specific to the infecting agent and their first function is to help the body recognise and kill the foreign organisms. The antibodies formed remain in the body and recognise and attack the same organism if it enters the body again. This prevents the organism from causing infection and disease, and is known as immunity. Protection against many infections can be provided artificially by means of vaccines derived from altered forms of infecting organisms. These vaccines stimulate the immune system to produce antibodies in the same way as genuine infection, without actually causing the disease. As each organism stimulates the production of a specific type of antibody, a different vaccine must be used for each disease. The yellow fever vaccine provides immunity against yellow fever. Immunity occurs within 7 to 10 days of vaccination.Some vaccines remain effective for a lifetime, but some need need to be updated after a few years. With the yellow fever vaccine a "booster" injection is needed after 10 years if protection against the disease is still required.The yellow fever vaccine is not given routinely in the UK, but it is recommended for people travelling to countries where the disease is found. Most of these countries require you to have an International Certificate of Vaccination, stating that you have been vaccinated against yellow fever, in order to enter the country. Your doctor or pharmacist will be able to tell you which countries these are. In order to be officially recognised, the vaccine must be administered at a designated vaccination centre and registered on an International Certificate. The International Certificate is valid for ten years from the tenth day after immunisation and immediately after re-immunisation.The vaccine is also recommended for laboratory workers who are handling infected material.

What is it used for?

  • Prevention of yellow fever


  • This vaccine should only be given to children under nine months of age if the risk of yellow fever is unavoidable, as there is a very small risk of the vaccine causing inflammation of the brain (encephalitis) in this age group.

Not to be used in

  • Babies under six months of age.
  • Allergy to eggs
  • HIV infection
  • People who are or who have recently received treatment that suppresses the activity of the immune system, eg long-term oral corticosteroids, chemotherapy, radiotherapy, medicines to prevent transplant rejection
  • People whose immune systems have a decreased ability to fight infection and disease, eg due to diseases such as leukaemia, lymphoma, HIV infection or immunodeficiency syndromes
  • Sudden feverish illness

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • The safety of this medicine for use during pregnancy has not been established. It is not recommended for use in pregnancy unless considered essential by your doctor. Seek medical advice from your doctor.
  • The safety of this medicine during breastfeeding has not been established. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

  • Headache
  • Rash
  • Fever (pyrexia)
  • An extreme allergic reaction (anaphylaxis)
  • Swollen glands (lymph nodes)
  • Pain in the muscles (myalgia)
  • Reactions at injection site
  • Weakness or loss of strength (asthenia)
  • Itchy rash (urticaria)
  • Inflammation of the brain (encephalitis)

The side effects listed above may not include all of the side effects reported by the drug's manufacturer.For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

This vaccine should not be given at the same time as a cholera vaccine or whole cell paratyphoid vaccine, as this may result in an insufficient immune response to the yellow fever vaccine. It is recommended that there is a period of three weeks between these vaccines and the yellow fever vaccine. If any other live virus vaccines are required, they should either be given at different sites at the same time, or with an interval of three weeks between them.

Other medicines containing the same active ingredients

Stamaril Yellow fever vaccine