MMR vaccine reaction with high fever, you can use drugs to reduce fever, if necessary, it is recommended to go to the hospital in time. Common adverse reactions to MMR vaccine include: fever (>39.4°C), which occurs in 5%-15% of cases and is usually seen within 6-12 days after vaccination; transient rash, which occurs in about 5% of cases; transient lymph node enlargement, which occurs in 5% of cases in children and 20% of cases in adults; and hypersensitivity reactions (windburns and erythema, or hives), which are usually mild and have been clearly identified as being caused by traces of the vaccine’s of neomycin or gelatin (rather than egg antigen) in the vaccine. Vaccine-induced adverse reactions are generally self-limiting and can resolve on their own after a certain period of time. If the patient is uncomfortable due to high fever, ibuprofen, acetaminophen, etc. can be taken to reduce the heat treatment, and if the symptoms continue to be unrelieved, it is recommended that immediate medical attention be sought. Clinical hyperthermia is risky, it is recommended to go to the fever clinic of the hospital as soon as possible, under the guidance of the doctor for treatment.