The MMR vaccine is known as the combined live attenuated measles-mumps-rubella vaccine. 2 doses of MMR vaccine are required, and under normal circumstances, the first dose is recommended to be administered at 8 months of age and the second dose at 18 months of age (i.e., 1.5 years old). This vaccine is mainly administered by subcutaneous injection, with a dose of 0.5 ml per dose. The recommended vaccination age in the National Immunization Program refers to the minimum age at which the vaccine can be administered (i.e., for the 2 doses of MMR vaccine, the first dose can be administered at the earliest age of 8 months, and the second dose can be administered at the earliest age of 18 months), and if there are no contraindications, the vaccine should be administered as early as possible when the child reaches the age at which the vaccine can be administered. If there are no contraindications, children should be vaccinated as early as possible when they are old enough to be vaccinated. If there is any discomfort after vaccination, they should go to the local hospital.