Fever after measles vaccine: what to know

Vaccination trains the immune system, and temporary fever can occur as the body responds. Some children may also be unsettled or develop mild swelling of glands. This reaction does not mean the child has measles; the vaccine cannot cause the full measles illness. A fever beginning well after the appointment, lasting longer than expected, or accompanied by a worsening cough, breathing trouble, or a marked rash may have another explanation.

Offer frequent fluids, keep clothing comfortable, and allow rest. Check how your child is behaving, drinking, and breathing rather than focusing only on the thermometer. Use fever medicine only as directed for the child’s age and weight, and never give aspirin to a child unless a clinician specifically says to do so. Keep the vaccination record and note when the fever began. A GP consultation can help if you are unsure whether symptoms fit a vaccine reaction.

Get urgent help if the child has trouble breathing, swelling of the face or throat, becomes unusually sleepy or difficult to wake, has a seizure, cannot keep fluids down, or develops a rapidly worsening rash. Contact a clinician for a persistent fever, poor drinking, fewer wet nappies, or a child who is getting worse. Mention the vaccine and the timing of symptoms.

Ask how to monitor the fever, which medicine and dose are appropriate, and whether the next vaccine appointment should proceed. Ask which symptoms would suggest measles or an allergic reaction rather than a routine response.