About the Vaccine

MMR and MMRV Vaccine Composition and Dosage

Three vaccines containing measles, mumps, and rubella virus are licensed for use in the United States.

  • M-M-R II® is a combination measles, mumps, and rubella (MMR) vaccine manufactured by Merck & Co, Inc.
  • PRIORIX® is a combination measles, mumps, and rubella (MMR) vaccine manufactured by GlaxoSmithKline Biologicals (GSK).
  • ProQuad® is a combination measles, mumps, rubella, and varicella (MMRV) vaccine.

M-M-R II and PRIORIX are fully interchangeable for all indications for which MMR vaccination is recommended. All three vaccines contain live, attenuated measles, mumps, and rubella virus. MMRV also contains live, attenuated varicella-zoster virus.

The lyophilized live MMR vaccines and MMRV vaccine should be reconstituted and administered as recommended by the manufacturers1,2,3.

For package inserts, see M-M-R II, ProQuad, PRIORIX


  1. Merck & Co. Inc. M-M-R II (Measles, mumps, and rubella virus vaccine live); 2009.
  2. Merck & Co. Inc. ProQuad (measles, mumps, rubella and varicella virus vaccine live lyophilized preparation for subcutaneous injection). 2011.
  3. GlaxoSmithKline Biologicals SA. Package insert: PRIORIX (measles, mumps, and rubella vaccine, live). 2022.

MMR Vaccine Effectiveness and Duration of Protection

Vaccine Effectiveness

One dose

  • 1 dose of MMR vaccine is—
    • 93% effective for measles (range: 39%–100%)
    • 78% effective for mumps (range: 49%−92%)
    • 97% effective for rubella (range: 94%–100%)

Two doses

  • 2 doses of MMR are—
    • 97% effective for measles (range: 67%–100%)
    • 88% effective for mumps (range: 32%–95%)

Duration of Protection

People who receive MMR vaccination according to the U.S. vaccination schedule are usually considered protected for life against measles and rubella. While MMR provides effective protection against mumps for most people, immunity against mumps may decrease over time and some people may no longer be protected against mumps later in life.

  • Both serologic and epidemiologic evidence indicate that vaccine-induced measles immunity appears to be long-term and probably lifelong in most persons.
  • While the effectiveness of two doses of MMR against mumps is high, serologic and epidemiologic studies suggest this effectiveness decreases with time. A person with a decreased immune response after time may then become infected when exposed to mumps virus through close contact with a person with mumps. A third dose of MMR can provide added short term protection for those who are likely to have close contact with a mumps patient during an outbreak.
  • Studies indicate that one dose of vaccine confers long-term, probably lifelong, protection against rubella.

Vaccine Safety

The United States’ long-standing vaccine safety program closely and constantly monitors the safety of vaccines. See in-depth information about the safety of each FDA-approved vaccine: