Measles and rubella are very common infectious diseases in children that are spread by airborne droplets. Children are not naturally immune to either measles or rubella and are easily infected, especially in crowded public places and close contact between children, which is likely to increase the chance of being infected. Therefore, it is very important for every child to be vaccinated against measles. The use of each drug, however, has its own contraindications. Contraindications to measles vaccination include the following: 1. Patients with colds and fevers should not be vaccinated. It is very common for children to catch a cold. When a child is in a cold state or has other diseases that cause a fever, it is not suitable for vaccination against measles. At the same time, other vaccinations should also be prohibited, otherwise the child’s body temperature will gradually rise, inducing disease or aggravating the condition of the disease. 2. Patients recovering from infectious diseases should not be vaccinated. If a child is suffering from an infectious disease and is recovering from treatment or has had acute infectious disease exposure, children who have not spent the quarantine period are not suitable for leprosy vaccination and other vaccinations, otherwise it is very easy to have adverse reactions or to aggravate the infectious disease. 3, patients with allergies should not be vaccinated. Leprosy vaccine has a strong allergen, if the body is more sensitive, after vaccination leprosy vaccine, will produce a strong allergic reaction. Therefore, patients with allergies should not be vaccinated against leprosy. Likewise, children with asthma, eczema and hives are not suitable for leprosy vaccination. This is because it can cause fainting, seizures or shock in children. 4. Children under 1 year of age should not be vaccinated because of the risk of neurological deafness. 5. Children who have been injected with immunoglobulin should not be vaccinated for the time being, and the vaccination should be given only after an interval of 1 month. Therefore, before and after the leprosy vaccination, it is important to ensure that the child is in a healthy state, such as accidentally catching a cold and fever or having other symptoms of infection, which can reduce the child’s immune response to the leprosy vaccine.