MMR is generally referred to as MMR3 vaccine, which needs to be administered when the child is 8 months and 18 months old. If the vaccination is not given at the required time, a catch-up vaccination is required. The MMR vaccine can be used to prevent measles, rubella, and mumps diseases. It is recommended that a child can receive one dose of MMR vaccine at 8 months and 18 months of age. If you miss the vaccination, you should follow your doctor’s recommendation to get a catch-up MMR vaccination at the right time. If both doses of MMR vaccine are missed, two doses of MMR vaccine should be given at intervals of not less than 28 days. It is recommended that pregnant women, people who are allergic to the components of MMR vaccine, people with fever and respiratory disease, active tuberculosis, malignant disease, malignant tumors, acute stage of chronic diseases, immunocompromised people, and patients with uncontrolled epilepsy or neurological diseases are prohibited from receiving MMR vaccine. It is recommended that the MMR vaccine can be administered within the prescribed time under the guidance of a doctor, and at the same time, after receiving the MMR vaccine, you need to observe the vaccination site for half an hour before leaving. Prevent the MMR vaccination from adverse reactions such as redness and swelling of the inoculated part, fever, allergy and so on.