Yellow fever side effects. Who should-or shouldn't-be vaccinated against yellow fever
Yellow fever is a mosquito-borne (transmitted via mosquito bites) viral infection. It is common (endemic) in equatorial Africa and in areas of South America, but not in Asia.
As per WHO (World health organization) Yellow fever is deadly in 20%–50% of cases.
Proof of yellow fever vaccination can be legally required:
✓ To enter endemic yellow fever countries ("endemic" meaning the disease is common and risk of yellow fever transmission is high) ): Ghana, Nigeria, Niger, and others
✓ To enter some countries where yellow fever is not endemic if you are arriving from a yellow fever country, including an airport of such a country that you were in for more than 12 hours.
Some yellow fever zone countries (Kenya, Tanzania, etc.) recommend yellow fever vaccination but do not have a legal vaccination requirement for it for travelers arriving from non-yellow fever zone countries. Travelers to those countries need vaccination for their own protection.
Who can get yellow fever vaccine?
Yellow fever vaccine is approved for anyone over 9 months of age if there are no contraindications.
It is administered at specialized CDC (Centers for Disease Control and Prevention) health care clinics.
Who should not get yellow fever vaccine?
Yellow fever vaccine is a live-virus vaccine grown in chicken embryos (chicken protein). After vaccination, a low level of virus in the blood often develops within three to seven days. It can persist for up to three weeks.
Because this is a live attenuated vaccine, certain categories of people are advised to not get it (they are at a increased risk of getting side effects due to weakened immune system):
✓ People with primary immunodeficiencies
- autoimmune lymphoproliferative syndrome (ALPS)
- APS-1 (APECED)
- CARD9
- chronic granulomatous disease (CGD)
- ocongenital neutropenia syndromes
- common variable immunodeficiency (CVID)
- CTLA4 deficiency
- DOCK8 deficiency
- glycosylation disorders with immunodeficiency
- hyper-immunoglobulin E syndromes (HIES)
- PI3 Kinase disease
- PLAID
- Severe combined immunodeficiency (SCID)
- STAT3 dominant-negative disease
- WHIM syndrome
- X-linked agammaglobulinemia (XLA)
- X-linked lymphoproliferative disease (XLP)
✓ Transplant recipients
✓ Patients on immunosuppressive and immunomodulatory therapies
✓ Patients with human immunodeficiency virus (HIV) whose CD4 count is <200/mL
✓ Page < 6 months of age
✓ People allergic to a vaccine component
✓ People with thymus disorders
When is caution advised?
Certain categories of people should be cautious about being vaccinated against yellow fever. According to CDC the risk of getting sick from yellow fever disease and dying from it should be balanced against the risk of serious side effects from the vaccine.
Caution is advised for these people:
✓ Travelers > 60 years of age
✓ Travelers 6–8 month of age
✓ Pregnant woman
✓ Breastfeeding females
If travel is unavoidable and the risk of yellow fever disease exposure are felt to outweigh the risks that accompany vaccination, the person can be vaccinated.
Consultation with personal health care provider for a medical advice is encouraged
If the risk of vaccine side effects outweighs the risk of yellow fever virus exposure, a medical waiver to fulfill any international health regulation requirement should be issued.
Yellow fever vaccine waver
In some instances, proof of yellow fever vaccination (international certificate of vaccination or prophylaxis) is required for travel but is contraindicated.
For circumstances in which yellow fever vaccine documentation must be presented to international customs officials, a medical letter of waiver can be provided.
But before considering a waiver, a traveler should seriously consider changing their itinerary to not go to high-risk yellow fever areas.
A medical letter of waiver is usually obtained from a specialist doctor or primary care doctor who has documented the reason for the waiver.
Here is a photo of yellow fever medical waiver:
Vaccine certificate
A yellow fever vaccine certificate is valid for life, no matter when it was issued.
How soon before traveling should yellow fever vaccination occur?
Ideally, the vaccine should be obtained 10 days before traveling. This corresponds to the time during which the majority of people develop protection.
Yellow fever vaccine booster dose
Who should get a yellow fever vaccine booster?
For most people, a single dose of yellow fever vaccine provides lifelong immunity.
However, some people may need a yellow fever booster:
✓ Travelers going to areas where yellow fever is endemic are who got their last yellow fever more than 10 years ago
✓ Some countries require yellow fever vaccine every 10 years, with proof being required for entry (Countries of West Africa:Ghana, Nigeria, Angola, Burundi, etc.).
Please keep in mind that CDC (Centers for Disease Control and Prevention) recommendations can differ from requirements of the country of entry.
✓ If the vaccine is required for entry and the traveler has lost the original yellow fever vaccine certificate and cannot get a copy. Each yellow fever vaccine certificate is an official legal document that has an administered vaccine lot number and expiration date on it. (An extra yellow fever shot will not have any additional negative medical side effects.)
Getting other vaccines with the yellow fever shot
Yellow fever vaccine can be administered either at the same time as or 30 days apart from other live vaccines.
Some examples of live vaccines are measles, mumps, and rubella (MMR), varicella, and rabies.
Other inactivated vaccines or oral live vaccines (e.g., Typhoid) can be given by health care clinic simultaneously or at any time before or after yellow fever vaccination.
Yellow fever vaccine side effects
As with any vaccination or medication, yellow fever vaccine has side effects.
Most of the side effects are common and very mild, but some can be very serious, even life threatening.
Most common side effects
Reactions to yellow fever vaccine are generally mild and include pain at injection site, headache, muscle ache, and low-grade fever.
One in four people might experience those side effects.
Serious side effects
Rarely, people develop a severe reaction:
- Allergic reaction, including difficulty breathing or swallowing (anaphylaxis)-1 in 55,000 people
- Swelling of the brain, spinal cord, or surrounding tissues (encephalitis or meningitis)-1 in 125,000 people
- Guillain-Barré syndrome, an uncommon sickness of the nervous system in which a person’s own immune system damages the nerve cells, causing muscle weakness and, sometimes, paralysis-1 in 125,000 people
- Internal organ dysfunction or failure—1 in 250,000 people