The 13-valent pneumonia fever lasts about 3 days. The 13-valent pneumonia vaccine is a biological preparation, which is an antigenic substance. When injected with the 13-valent pneumonia vaccine, the antigen enters the body and activates the body’s immune system, causing the body to produce an immune response and generate corresponding antibodies. In the process of generating antibodies, a large number of lymphocytes in the body will be caused to participate in the response, resulting in fever, diarrhea and other symptoms. The process from antigen entering the body to the production of antibodies takes about 3 days, so the fever time of the 13-valent pneumonia vaccine will not be more than 72 hours, and the fever caused by the 13-valent pneumonia vaccine is mostly low, and the body temperature is rarely more than 38°C. If the 13-valent pneumonia vaccine is given after the injection, the body will produce the corresponding antibodies, causing the body to produce an immune response. If the body temperature exceeds 38℃ for more than 72 hours after the vaccination, it may be combined with other infections, and further examination is needed to find out the specific cause.