Babies may have fever after vaccination due to vaccine side effects or their own immune function, and low fever sometimes lasts for less than a week. The temperature of low fever within a week is usually not high, parents can take physical cooling treatment, you can drink more water, wipe with warm water or auxiliary paste anti-fever paste can play a role in reducing fever. At the same time, parents should pay attention to a light, easy-to-digest diet and observe closely, which usually returns to normal within a week or so on its own. If the baby is still in a low fever state a week after vaccination, and the baby’s mental state is not particularly good, or accompanied by abnormal gastrointestinal and digestive functions, etc., it is necessary to take the baby to the hospital under detailed examination by the doctor to exclude whether the low fever is caused by other disease factors, so that further treatment can be given.