There is generally no strict limit to how long the MMR vaccine can be delayed, and it is best to be able to get vaccinated on time, and if possible to catch up within 1 month if there is a special reason. MMR vaccine is used to prevent acute respiratory infections such as measles, mumps and rubella. Usually children receive the 1st dose at 8 months of age, and the second dose can be given at 1~2 years of age. If the child has a cold, fever, cough and other diseases during the vaccination period, the child needs to be cured before the MMR vaccine can be given. There is no strict limitation on the exact delay of MMR vaccination, but if the child has no disease, it is recommended that the child who has reached the age of 8 months should be vaccinated with MMR vaccine as early as possible. If conditions do not permit MMR vaccination, try to catch up within 1 month. Note that a longer delay may not have a preventive effect. Parents are advised to bring their children for MMR vaccination on time and regularly, and need to take care of them after vaccination to prevent infection.