Fever 5 days after MMR may be caused by adverse drug reaction, viral infection, bacterial infection, etc. It can be handled by physical cooling and medication. 1. Adverse drug reaction: fever 5 days after mumps vaccination may be an adverse reaction to a drug. Physical cooling can be done by wiping the forehead, armpits and other parts of the body with a warm wet towel. At the same time, you need to drink more water and pay attention to rest. Severe symptoms can be treated with drugs such as ibuprofen extended-release capsules and acetaminophen under the guidance of a doctor. 2. Viral infection: 5 days after the MMR, the patient did not take good care of the wound, which may lead to virus invasion and cause fever. This situation can be treated with cefdinir, amoxicillin and other drugs under the guidance of doctors. 3. Bacterial infection: 5 days after the mumps, patients due to cold, not take good care of the wound and other conditions, may lead to bacterial invasion, which can also lead to fever symptoms. Amoxicillin, roxithromycin and other drugs can be used under the guidance of the doctor. Fever after 5 days of MMR, it is recommended to go to a professional doctor for examination, to clarify the specific cause, and then actively cooperate with the doctor for treatment. The use of medication needs to be under the guidance of a doctor.