Measles, mumps, and rubella virus vaccine (live) is an active immunizing agent that is given to protect against infections caused by measles, mumps, and rubella (German measles). It works by causing your body to produce its own protection (antibodies) against the virus.

Older children, adolescents, and adults born after 1957 should get at least one MMR shot if they have never had the measles or been vaccinated for the disease (or aren't sure if they have)—that is, if they don't have written documentation or other proof of immunity, according to the CDC.    *Jul 10, 2025*