Some infants may develop fever after vaccination. For most people it is generally more common to have a low fever, in which case no special treatment is needed, only physical cooling should be given. Wiping the skin of the forehead, extremities, armpits, neck, palms and feet with warm water helps to dissipate the heat, and it usually relieves itself in 1-2 days. There are a few infants who may have a high body temperature, even over 39℃, which may be accompanied by systemic reactions such as loss of appetite, nausea and vomiting. At this time, in addition to warm water baths and physical cooling, it is also necessary to take appropriate hydration and, if necessary, antipyretic drugs under the guidance of a doctor. If you still have fever after 2-3 days of vaccination, it is also possible that other infections may develop secondary to the decrease in body resistance, and you should go to the hospital for consultation.