Symptoms after the yellow fever vaccine

A sore arm, redness, mild swelling, headache, muscle aches, tiredness, or a low fever can occur as the immune system responds. These effects generally settle without specific treatment. A delayed fever or rash can also occur, so note when symptoms began and whether they are improving. Vaccine symptoms are different from yellow fever infection, which is acquired through an infected mosquito rather than caused by the injection.

Rest, drink fluids, and keep the injection area clean. A cool compress may ease local discomfort. Ask a pharmacist or clinician which pain or fever medicine is suitable for you, especially if you are pregnant, have a long-term condition, or take regular medicines. Keep your vaccination record and tell healthcare staff the vaccine name and timing if you need advice.

Get urgent help for difficulty breathing, swelling of the face or throat, widespread hives, fainting, confusion, a seizure, or rapidly worsening weakness. Contact a clinician promptly for a high or persistent fever, severe headache, repeated vomiting, unusual bleeding, yellowing of the skin or eyes, or symptoms that are worsening rather than settling. Mention any recent travel and the date of vaccination.

Ask whether your symptoms fit a normal vaccine response, whether another illness could explain them, and which warning signs should prompt urgent review. You can also ask when you may resume exercise or travel and whether you need follow-up.