The first measles vaccines were available in 1963 and were replaced with a more effective vaccine in 1968. The combination measles vaccines in use today first became available in 1971 (MMR) and 2005 (MMRV). There are two combination vaccines available in the U.S. that protect against measles: the MMR (measles, mumps, and rubella) vaccine and the MMRV vaccine, which protects against measles, mumps, rubella, and varicella (chickenpox). They are both live attenuated, or weakened, vaccines, which means they contain weakened strains of the viruses they protect against. The MMR vaccine is approved for anyone 6 months of age and older. The MMRV vaccine is approved only in children ages 12 months to 12 years.