Fever after DTaP: what should you know?

DTaP helps the immune system recognise diphtheria, tetanus and pertussis. A raised temperature, fussiness, tiredness, reduced appetite, or soreness where the injection was given can occur as the body responds. The timing and intensity vary between children. A fever may also happen by coincidence when a child is developing an unrelated infection, so consider cough, breathing changes, rash, diarrhoea, or exposure to someone unwell rather than assuming the vaccine explains every symptom.

Check the temperature with a reliable thermometer and record when it began, how it was measured, and any medicine given. Offer frequent fluids or breastfeeds, dress your child comfortably, and allow rest. Keep the injection area comfortable; do not rub it vigorously. Use fever medicine only when advised for your child’s age, weight, and health, and follow the product directions. Do not give aspirin to a child. Avoid cold baths or alcohol rubs, which can cause discomfort.

Contact a clinician promptly if the fever is persistent, the child is becoming less responsive, is not drinking, has noticeably fewer wet nappies, or seems to be getting worse. Seek emergency help for trouble breathing, a seizure, blue or grey lips, severe sleepiness, a rapidly spreading rash, or swelling of the face or throat. Infants who are very young or children with significant medical conditions need a lower threshold for assessment; call their healthcare team for tailored advice.

Ask whether the temperature and timing fit a vaccine reaction, what dose of fever medicine is suitable for your child, and whether the next scheduled dose should proceed. Tell the clinician about allergies, previous vaccine reactions, medicines, and any symptoms that appeared before the injection.