Five-month-old babies with fever after vaccination, such as mental response is good, and no other abnormalities can be closely observed first, such as high fever, recurrent fever or depression, etc., need to actively seek medical attention. Preventive vaccination is very important for infants, can reduce and control the spread of related infectious diseases, but some babies can be vaccinated can appear vaccine reaction, such as increased body temperature, often low fever, and a shorter duration, the general spirit of the response is good, and there is no other obvious abnormal symptoms of discomfort, for this type of babies, you can first physical cool down the temperature, continue to observe. When five-month-old babies appear high fever, or repeated fever, poor mental response and lethargy, etc., need to pay attention to whether there are other abnormal symptoms, such as cough, rash or diarrhea and other symptoms, and actively consult the doctor to clarify the cause of fever and treatment. For example, acute upper respiratory infection, body temperature over 38.5 ℃ need to use acetaminophen to reduce fever, etc., if the combination of bacterial infections, can be used in accordance with the doctor’s instructions, such as ceftazidime, to avoid delayed treatment. It is recommended to consult a physician for evaluation and judgment by a specialist if necessary.