Fever after vaccination is a normal reaction after vaccination. The most important thing is to observe the change of body temperature. For example, if the temperature is between 37.2℃-38.5℃, it is called hypothermia and needs to be treated with physical cooling, which requires applying cooling patches, drinking more warm water and wiping the neck, armpits and thighs with warm water to improve the situation. If the body temperature is between 38.5℃-39℃, oral antipyretic drugs are needed to deal with it. For example, ibuprofen suspension, also need to drink more warm boiled water and with physical cooling to come down as soon as possible to prevent high fever convulsions. Fever after vaccination can subside in about no more than 3 days, which is the most normal reaction. If the fever persists for more than 3 days, or if other symptoms appear, such as rash, hard nodules, irritability, violent crying, etc., you need to go to the hospital and let the doctor check the body to find the cause of the fever.