What is the yellow fever vaccine?

Yellow fever is a viral illness spread through mosquito bites in certain parts of the world. The vaccine is used for prevention, not to treat symptoms after an infection has begun. A travel-health clinician considers your destination, planned activities, previous vaccination records, age, pregnancy status, immune system, and allergy history. Some destinations may also require proof of vaccination for entry, so travel paperwork deserves attention alongside medical protection.

Arrange a travel consultation well before departure so there is time to review whether the vaccine suits you and to receive any required documentation. Bring a list of medicines, allergies, prior vaccines, and details of every country or transit stop on your itinerary. Continue mosquito-bite prevention during travel by using repellent, covering exposed skin where practical, and following local public-health advice. Keep the vaccination certificate with your travel documents.

Seek urgent medical assessment during or after travel if you develop fever with severe headache, marked weakness, vomiting, yellowing of the skin or eyes, unusual bleeding, confusion, or breathing difficulty. Tell the clinician where you travelled and when mosquito exposure may have occurred. After vaccination, obtain urgent help for trouble breathing, swelling of the face or throat, widespread hives, fainting, or other rapidly worsening symptoms.

Ask whether each destination and transit country changes the recommendation, whether you need an entry certificate, and whether your health conditions or medicines affect suitability. It is also useful to ask which other travel vaccines and mosquito precautions fit your route.