When should children get the second MMR/MMRV shot?
The second dose is usually given when the child is 4-6 years old, or before he or she enters kindergarten or first grade. However, the second dose can be given anytime as long as it is at least four weeks after the first dose. MMRV can only be given through age 12 years. How effective is this vaccine? The first dose of MMR vaccine produces immunity to measles in 95-98% of children vaccinated. The reason for the second dose is to protect those persons who did not become immune after one dose. After two doses of measles vaccine, 99% of persons become immune to the disease. Which adolescents and adults should receive the MMR vaccine? In general, adults born before 1957 are likely to have had measles, mumps, and rubella during childhood and so are assumed to be immune. Exceptions to this guideline are women who want to become pregnant (see rubella section) and persons who work in medical facilities (see next question). All persons born in or after 1957 should be immune to measles by having
