For MMR vaccine, the 1st dose is usually given after 8 months of age, and there is no indication of when the 1st dose should be given at the latest. If there are no other contraindications, in principle, it is recommended to receive the vaccination as early as possible to obtain the immunization effect earlier. MMR vaccine is a combined vaccine, which mainly stimulates the body to produce antibodies through vaccination, and can help prevent diseases such as measles, mumps and rubella. Generally, the first vaccination can be given at 8 months of age, the second vaccination is given at about 18 months of age, and if necessary, a booster vaccination can be given at about 5 years of age according to one’s own situation, and the immunity can be obtained for about 10 years after the whole vaccination. The first two doses of MMR vaccine are basic immunization, which should be given as early as possible according to the child’s physical condition and medical advice to produce good immunity effect and prevent infectious diseases. If the basic immunization is not available on time, consult the doctor at the vaccination site and follow the prescribed procedures for the full vaccination as soon as possible.