Infants with MMR fever can be physically cooled down, if the fever persists it is recommended to seek medical attention. MMR vaccine is mainly used for the prevention of measles, mumps, rubella vaccine for infants and young children born more than 8 months of age, some infants and young children will have adverse reactions such as swollen lymph nodes on the cheeks or neck, mild fever or rash after vaccination. Generally, the symptoms of fever after vaccination are mild and will resolve on their own after a period of time. Parents can use hot towels to apply external compresses on the forehead of infants to promote fever reduction. At the same time, you can let the baby drink more water and have sufficient rest. If your baby’s fever does not subside for a long time, you should consult a doctor and take appropriate treatment under the doctor’s guidance.