The MMR vaccine has greatly reduced the number of cases of measles, mumps, and rubella each year, including serious side effects (death from measles, brain infection from mumps, and birth defects and mental retardation from rubella in pregnant women). Fewer than one child in one million who get this vaccine has a serious allergic reaction or other severe problem. A survey of 50 years’ worth of data (more than 2,000 studies from around the world) found that there was not enough evidence to support a suspected link between the vaccine and an increased risk for autism or bowel disease in children.
A first dose is usually given at 12 to 15 months, followed by a booster at age four to six. Older children who missed these vaccines should have one dose of MMR. Children with a high fever or a severe allergy to neomycin should not be given the vaccine.