Fever will last for 1~3 days after the injection, if it exceeds this period, other diseases can not be ruled out. Generally speaking, fever is a normal adverse reaction after the injection, which can recover on its own after 1~3 days and will not last too long. During this period, there may be persistent fever or intermittent fever, generally take symptomatic measures to lower the temperature. If the fever persists for more than 3 days, it cannot be ruled out that it is caused by other diseases, such as lung infection, etc. At this time, it is necessary to carry out chest X-ray, blood test, etc., to clarify whether there are other parts of the infection, and at the same time, carry out targeted anti-infective treatment, according to the doctor’s instructions, do not use your own medication.