The Basics
What Causes Yellow Fever?
Yellow Fever is a serious viral infection spread by the bite of infected mosquitoes (usually the Aedes or Haemagogus species). It is found in tropical areas of Africa and South America. The “yellow” in the name refers to the jaundice that affects some patients. While many infections are mild, the disease can cause severe liver damage and life-threatening complications.
Vaccination Overview
The Yellow Fever Vaccine (Stamaril)
| Feature | Details |
| Name of Vaccine | Stamaril (Live-attenuated vaccine). |
| Number of Doses | A single-dose injection. |
| When to get it | At least 10 days before travel for the vaccine to be effective and for the certificate to become valid. |
| The Booster | For most people, a single dose now provides lifelong protection. Routine boosters are no longer required. |
| How it is given | Administered as a subcutaneous or intramuscular injection. |
| Legal Document | You will receive an International Certificate of Vaccination or Prophylaxis (ICVP). |
Important Legal Requirements
The Yellow Fever Certificate (ICVP)
Many countries require proof of vaccination (the “Yellow Book”) if you are arriving from a country where Yellow Fever is present.
Validity: The certificate only becomes valid 10 days after your injection.
Loss of Document: If you lose your certificate, you may need a duplicate from the centre that vaccinated you or, in some cases, a re-vaccination.
Exemptions: If you cannot have the vaccine for medical reasons, a “Medical Exemption Certificate” must be issued by a registered Yellow Fever Centre.
Safety & Side Effects
Potential Side Effects
The vaccine is highly effective, but because it is a “live” vaccine, it can cause mild reactions:
Headache, muscle aches, and a low-grade fever within 5–10 days of the shot.
Local:Â Soreness or redness at the injection site.
1. YEL-AND (Yellow Fever Vaccine-Associated Neurotropic Disease)
This is a rare condition where the vaccine affects the nervous system.
Symptoms: Can include high fever, severe headache, confusion, or seizures.
Risk Groups: It is slightly more common in infants under 9 months and adults over 60 years of age.
Onset: Typically occurs within 2 to 56 days after receiving the vaccine.
2. YEL-AVD (Yellow Fever Vaccine-Associated Viscerotropic Disease)
This is an extremely rare but severe reaction that mimics a natural Yellow Fever infection, causing damage to the internal organs.
Symptoms: Can include fever, malaise, muscle pain, and progress to liver or kidney failure.
Risk Groups: The risk is higher for first-time vaccinees, individuals over 60, and those with a history of thymus gland disorders (such as Myasthenia Gravis or surgical removal of the thymus).
Onset: Usually occurs within 10 days of vaccination.
Our Clinical Commitment: Because of these risks, we perform a robust clinical assessment before administering the vaccine. If you are over 60 or have a weakened immune system, we will weigh the risk of the disease against the risk of the vaccine to ensure your safety.
Recognising Symptoms
Symptoms of Yellow Fever
Symptoms usually appear 3 to 6 days after the mosquito bite.
Phase 1 (Acute): Sudden fever, chills, severe headache, back pain, and nausea.
The “Remission”: Most people recover after Phase 1. However, some feel better for 24 hours before entering a more serious stage.
Phase 2 (Toxic): Return of high fever, Jaundice (yellowing of skin/eyes), dark urine, and abdominal pain.
Severe Signs: Bleeding from the mouth, nose, eyes, or stomach (vomiting blood).
Additional Precautions
Bite Prevention
The mosquitoes that carry Yellow Fever can bite during the day and night.
Repellent: Use 50% DEET on exposed skin.
Clothing: Wear long-sleeved, light-coloured clothing.
Sleep Safety: Use a mosquito net if your room is not air-conditioned or screened.
FAQ
Can I get the Yellow Fever vaccine if I am over 60?
Yes, but only after a strict medical consultation. There is a slightly higher risk of side effects for first-time vaccinees over 60, so your travel plans and health history must be balanced.
Does the certificate really last for life?
Yes. Under International Health Regulations (2016), the ICVP is now valid for the life of the person vaccinated. You do not need a booster for administrative travel purposes.
Why do you ask so many questions about my age and my thymus gland?
Because the risk of rare complications like YEL-AVD and YEL-AND increases in those over 60 or those with thymus issues, we need to be incredibly thorough. If the risk of the vaccine outweighs the risk of catching Yellow Fever at your destination, we may issue a Medical Exemption Certificate instead of the vaccine.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as medical advice, diagnosis, or treatment. While we strive to provide accurate health information, it is not a substitute for the professional judgment of a healthcare provider. Always seek the advice of your physician or other qualified health professional with any questions you may have regarding a medical condition or vaccination schedule. Never disregard professional medical advice or delay seeking it because of something you have read on this website.