Fever is a common adverse reaction after vaccination. The principles of treatment are: when the body temperature exceeds 38.5℃, the child’s mental state is bad and drowsy, you can give your baby the antipyretic medicine Merlin or ibuprofen to reduce fever; you can also use pediatric antipyretic suppositories to reduce fever in the anus. At the same time, let the baby drink more warm water, wipe the baby’s body with warm water, paste a fever patch can help the baby cool down. If the baby’s body temperature is below 38.5℃ and the child is in good spirits, you can observe first, not to take antipyretic drugs, and take physical cooling measures, such as applying antipyretic patches and taking warm baths. Generally, the fever caused by vaccination appears within 24 hours after vaccination, and the temperature lasts 1-2 days and then comes down. If the fever lasts more than 48 hours, you need to go to the hospital.