Yellow fever vaccine: neurological side effects

Neurological symptoms involve the brain, spinal cord or nerves. They may include a severe headache, altered alertness, unusual behaviour, a seizure, weakness, loss of coordination, numbness, trouble speaking or a change in vision. These symptoms can have many causes and require a clinician to assess the whole situation.

A mild headache or tiredness can occur after vaccination and is different from a new focal weakness, confusion or a seizure. The change in function is important: if someone cannot communicate, walk, use a limb or stay awake as usual, treat that as urgent.

Arrange urgent assessment and do not drive yourself if you feel confused, dizzy, weak or have a vision change. If possible, have another person bring the vaccination record, including the product name and date, and describe the order in which the symptoms appeared.

For a planned dose, tell the clinician about any previous serious neurological illness or reaction to a vaccine. Yellow Fever Vaccination discussions should also cover medicines or treatments that affect the immune system.

Call emergency services for a seizure, loss of consciousness, sudden weakness on one side, difficulty speaking, severe confusion, a severe headache with neck stiffness, or breathing difficulty. These warning signs need immediate care regardless of their possible relationship to a recent vaccine.

Ask what conditions are being considered, which tests or observations are appropriate, and what symptoms should trigger a return to urgent care. Before any future vaccination, ask how this event should be documented and reviewed.