Yellow Fever Vaccine
Indications
Yellow Fever Vaccine provides protection against a serious infectious disease called yellow fever. Yellow fever occurs in certain areas of the world and is spread to man through the bites of infected mosquitoes.
Yellow Fever Vaccine is given to people who:
- are travelling to, passing through or living in an area where yellow fever occurs,
- are travelling to any country that requires an International Certificate of Vaccination for entry (this may depend on the countries previously visited during the same trip),
- may handle infectious materials such as laboratory workers.
To obtain a valid vaccination certificate against yellow fever, it is necessary to be vaccinated in an approved vaccination centre by a qualified and trained healthcare professional so that an International Certificate of Vaccination can be issued. This certificate is valid from 10 days after the first dose of vaccine. In some circumstances, when a booster is needed, the certificate (see Section 3) is valid immediately after the injection.
Pharmacology
Live, attenuated virus stimulates active immunity to Yellow fever; conveys active immunity via stimulation of production of endogenously produced antibodies. Yellow fever vaccine is used for active immunisation against yellow fever. Each dose (usually 0.5 ml) contains at least 1000 mouse LD50 units.
Dosage And Administration
Yellow Fever Vaccine is given as a single, 0.5 millilitre dose to adults and children from 6 months of age. The first dose should be given at least 10 days before protection from yellow fever is needed. This is because it takes 10 days for the first dose of vaccine to work and provide good protection against the yellow fever virus. The protection provided by this dose is expected to last at least 10 years and maybe life-long. In some circumstances, a booster with one dose (0.5 millilitre) may be needed:
- if you or your child had an insufficient response to the first dose and you or your child continue to be at risk for yellow fever virus infection.
- or depending on official recommendations.
Yellow Fever Vaccine is given as an injection by a qualified and trained healthcare professional. It is usually injected just underneath the skin but it can be given into a muscle. It must not be injected into a blood vessel.
Interaction
Tell your healthcare professional if you are taking, have recently taken or might take any other medicines. If you have recently had any treatment or medicine which may have weakened your immune system, the vaccination must be delayed until your laboratory results show that your immune system has recovered. Your doctor will advise you when it is safe for you to be vaccinated. Yellow Fever Vaccine can be given at the same time as measles vaccine or vaccines against typhoid fever (those containing the Vi capsular polysaccharide) and/or hepatitis A. Vaccination with Yellow Fever Vaccine may lead to false positive results of blood tests for dengue or Japanese encephalitis. If you or your child have in the future such tests prescribed, please inform your doctor about this vaccination.
Contraindications
Do not use Yellow Fever Vaccine if you or your child are allergic to:
- the active substance, or
- any of the other ingredients of this vaccine (listed in Section 6), or
- eggs or chicken proteins.
- have experienced a severe allergic reaction after a previous dose of any yellow fever vaccine,
- is less than 6 months old,
- have a poor or weakened immune system for any reason, such as illness or medical treatments (for example high-dose steroids, or any other medicines that affect the immune system, or chemotherapy). If you are unsure whether the medication may affect your or your child’s immune system, discuss with your healthcare professional before the vaccine is administered.
- have a weakened immune system due to HIV infection. Your healthcare professional will advise you if you or your child can still receive Yellow Fever Vaccine based on the results of your blood tests,
- are infected with HIV and have active symptoms due to the infection,
- have a history of problems with your or your child’s thymus gland or have had the thymus gland removed for any reason,
- have an illness with a high or moderate fever or an acute illness. The vaccination will be postponed until you or your child have recovered.
Side Effects
The following serious side effects have sometimes been reported: Allergic reactions:
- Rash, itching or hives on the skin
- Swelling of the face, lips, tongue or other parts of the body
- Difficulty swallowing or breathing
- Loss of consciousness
Pregnancy And Lactation
If you are pregnant, or breastfeeding, think you may be pregnant or are planning to have a baby, ask your healthcare professional for advice before being vaccinated. You should not receive Yellow Fever Vaccine during pregnancy or breastfeeding unless this cannot be avoided. Also, it is recommended that you do not become pregnant within one month after receiving Yellow Fever Vaccine. Your healthcare professional can advise you on whether it is essential that you are vaccinated. In case vaccination is needed, it is recommended to interrupt breastfeeding for at least 2 weeks after you receive Yellow Fever Vaccine. In case you receive the vaccine while pregnant or breastfeeding, consult your healthcare professional.
Precautions And Warnings
It is important to tell your healthcare professional if any of the points below apply to you or your child. If there is anything you do not understand, ask your healthcare professional to explain.
Before using Yellow Fever Vaccine, it is important that you complete a risk assessment with a trained healthcare professional, to determine whether you should receive the vaccine.
- If you are over 60 years old or if your child is less than 9 months as you have an increased risk of certain types of severe but rare reactions to the vaccine (including serious reactions that affect the brain and nerves, and vital organs). You will only be given the vaccine if the risk of infection with the virus is well established in countries where you are going to stay.
- If your child is aged 6 to 9 months. Yellow Fever Vaccine may be given to children aged between 6 and 9 months only in special situations and on the basis of current official advice.
- If you or your child are infected by the HIV virus but do not have active symptoms due to the infection. Your healthcare professional will advise if Yellow Fever Vaccine can be given based on the results of laboratory tests and specialist advice.
- If you or your child have any bleeding disorder (such as haemophilia or low level of platelets) or are taking any medicines that stop the blood clotting normally. You can still be given Yellow Fever Vaccine provided that it is injected under the skin and not into muscle.
- If you had any allergic reaction to latex. The tip cap of the pre-filled syringe contains a natural rubber latex derivative which may cause an allergic reaction.
Storage Conditions
Keep out of the sight and reach of children. Do not use this vaccine after the expiry date which is stated on the carton after EXP. The expiry date refers to the last day of that month. Store in a refrigerator (2°C-8°C). Do not freeze.