On Apr. 22, 1971, the measles, mumps, and rubella virus (M-M-R II) vaccine Live developed by Maurice Hilleman was licensed to Merck.

Measles (rubeola) is a highly contagious respiratory disease spread by coughing, sneezing, or simply being in close contact with an infected individual. The disease can be spread even when the rash is not visible and most measles cases in the U.S. resolve without complication, though serious complications can occur.

Today, M-M-R^®_II is indicated for active immunization for the prevention of measles, mumps, and rubella in individuals 12 months of age or older. The first dose of M-M-R^®_II is administered at 12 to 15 months of age and the second dose of M-M-R^®_II is administered at 4 to 6 years of age.