MMR is vaccinated after 8 months of age. MMR is a vaccine against 3 diseases, including measles, rubella and mumps. It is usually given in 2 shots, the 1st shot from 8 months of age, and the 2nd shot at around 1.5 and 2 years of age respectively, and the one given around 6 years of age is a booster shot. MMR must be given to children at least 8 months of age and is not suitable for children too young to be immunocompromised. If a child is immunocompromised or suffers from an underlying disease that makes him or her unsuitable for vaccination in early childhood, he or she can be vaccinated at around 5 years of age when his or her condition is well controlled and his or her health is basically restored. Therefore, children of the appropriate age must be vaccinated against MMR, and it is best to consult a doctor in time if any abnormality occurs in the course of vaccination, in order to avoid the occurrence of adverse reactions as much as possible.