Yellow fever vaccine is used to prevent the recipient from becoming infected with the yellow fever virus. It works by promoting the production of natural protection (antibodies) within the recipient. The yellow fever vaccine is a live culture that is propagated within living leucosis virus-free chicken embryos.
Vaccination against yellow fever is recommended for travel to areas where there is a prevalence of yellow fever. This includes but is not limited to sub-Saharan Africa, parts of Central America and the Caribbean and most of South America. Countries at risk of yellow fever transmission include (but are not limited to):
Some countries require yellow fever immunization and usually a certificate of vaccination before they will admit entry to the country. Countries that require proof of yellow fever vaccination for all arriving travelers include (but are not limited to):
Your doctor will issue the International Certificate of Vaccination or Prophylaxis (ICVP) when the vaccine is administered and this will become valid 10 days after the vaccination date. You will often be asked to present this at border control when entering a country that requires a yellow fever vaccination. If you lose your certificate they can be reissued, but you will be required to supply details about the vaccination date, location and batch to get a replacement certificate.
Vaccination is recommended for all persons over nine months of age. Pregnant women, however, should only be vaccinated when the risk of infection is very high. In cases when they must travel to an area under yellow fever epidemic and they cannot be protected from mosquito bites, the vaccine is still highly recommended.
There is no adequate evidence to determine infant risk during breastfeeding following the yellow fever vaccine. Potential risks should be considered before receiving the vaccine when breastfeeding.
People over the age of 60 are also advised against receiving the vaccine except in cases where there is a very high risk of exposure.
Yellow fever vaccination provides lifelong protection for most people but certificates are valid only for 10 years, beginning 10 days after the first vaccination. If a second booster vaccination is administered, the certificate will be valid for 10 years from this date of administration.
Authorized professionals can only administer yellow fever vaccination at authorized centers. Not all doctors are able to administer the yellow fever vaccination.
Not all persons administered with the vaccine may be protected by it. Since the vaccine may not protect everyone who receives it completely, it is very important to take other measures to avoid infection in at-risk areas. Staying indoors during twilight and during darkness when mosquitoes are most prevalent, wearing effective mosquito repellent, using mosquito nets and wearing protective clothing will all help you to stay free of yellow fever infection.
The yellow fever vaccine can cause a very serious allergic reaction called anaphylaxis in some patients. This is a life-threatening condition and requires immediate medical attention to be administered. The authorized vaccine sites are prepared to deal with such anaphylaxis and will have the appropriate response medicines available at hand.
Side effects from the yellow fever vaccine are not usually immediate. They can take up to 30 days to occur following administration of the vaccine to you. Any side effects should be reported immediately to a medical professional.
After receiving the vaccine common side effects include rashes, itching, swelling of the tongue and throat, or respiratory difficulties. If you experience any of these symptoms you should consult your doctor and tell them that you have recently received the yellow fever vaccine.
There is a minor risk of contraction of neurotropic disease or post-vaccinal encephalitis following receipt of the yellow fever vaccine. Side effects linked to these conditions include irritability, confusion, a stiff neck, vomiting, headaches or seizures. These reactions can be very serious, so you should seek medical advice as soon as possible.
Serious allergic reactions may also occur that affect a number of key internal organs. Fevers, dark urine, unusual tiredness, yellow skin, yellow eyes, rashes and headaches should all be reported to your doctor immediately if they occur.
The vaccine is also stored in conditions that expose it to latex. If you have an allergy to latex, you should forewarn your doctor before receiving the vaccine. You should also inform the doctor if you are taking any other medications as these may lower your immune system and increase your risk from receiving the vaccine.
The usual dosage of yellow fever vaccine for adults is 0.5ml subcutaneously at least 10 days before travel. In most cases, this will offer lifetime protection, but booster doses are recommended every 10 years if exposure continues as a risk.
The same dose of 0.5ml is administered to all patients equal to or greater than nine months in age.
A scratch, prick or puncture test will usually be carried out before the main dosage is administered. This is particularly important if the recipient is suspected to have an egg sensitivity.
Drugs can interact with one another when administered at the same time. In certain cases, this can prevent one or both of the drugs from working and in more serious cases they can react violently with one another putting your health in serious jeopardy. It is vitally important that you inform your doctor of any medicines, prescribed or unprescribed, that you may be taking at the time of vaccination. This includes recreational drugs, as these may impact the vaccine administration.
The yellow fever vaccine is not recommended with the following medicines:
The yellow fever vaccine is not usually recommended with the following medicines. In some cases, they may be prescribed together, but your doctor may wish to monitor you more closely or change the frequency or dosages of one:
The yellow fever vaccine can have an increased risk of certain side effects when you are taking the following medicines. Your doctor may still decide that both drugs are the best treatment for you:
The yellow fever vaccine can also have other interactions with foods, alcohol, and tobaccos. Ensure you tell your doctor if you have any medical conditions at all and if you have any existing allergies that you are aware of.
As well as advising the doctor about any allergies and current medicines being taken, the recipient should also discuss his or her medical history and current health with the doctor. Yellow fever vaccinations may not be administered where the patient suffers from other underlying medical conditions. The patient should inform the doctor of any of the following conditions:
The doctor should also be made aware of any addictions or dependencies that the patient has. This includes past addictions, even where the patient has successfully completed a rehabilitation treatment program.
The patient should also inform the doctor if they have a weak immune system. This can be a result of HIV, AIDS, cancer, leukemia, lymphoma, thymic disease, or because of a range of different conditions. In the case of an asymptomatic HIV infection, the patient should be vaccinated and monitored for possible side effects.
A medically trained member of staff is assigned to every yellow fever vaccination clinic to be responsible for the safe storage of this vaccine.
Recommendations for storage of the yellow fever vaccine include the following:
Yellow fever vaccination should be administered only by an authorized professional and only in cases where the recipient will be placed at risk of contracting yellow fever. The is a significant portion of sub-Saharan Africa and South America that is under yellow fever epidemic and many countries will require proof of vaccination before allowing you to enter.
The vaccine is administered as a live culture and as such can induce significant side effects. The most significant side effect is the immediate inducement of anaphylaxis, which is a server allergic reaction. Other side effects can take up to 30 days to occur, but they can also be very serious.
When considering a yellow fever vaccination it is important to be sure that you actually need to be vaccinated and to consider the genuine risks of vaccination. Elderly people, those aged under 9 months and pregnant ladies are highly recommended not to receive the vaccine. Those with other underlying medical conditions should also make these known to the medical professional and they may be advised against the vaccination and travel. Any other medicine that is being administered should also be made known to the medical professional before vaccination.
Following vaccination, you will receive an International Certificate of Vaccination or Prophylaxis (ICVP), which serves as proof of vaccination when crossing borders.