MMR vaccine


The MMR vaccine is a "3-in-1" vaccine that protects against measles, mumps, and rubella -- all of which are potentially serious diseases of childhood.

Alternative Names

Vaccine - MMR; Rubella vaccination; Mumps vaccination; Measles - mumps - rubella (MMR) vaccine



The MMR is one of the recommended childhood immunizations. Usually, proof of MMR vaccination is needed to go to school.

  • The first shot is given when the child is 12 to 15 months old. To make sure the child is properly protected, the vaccine must not be given too early.
  • A second MMR shot is given before a child enters school at 4 - 6 years, but may be given at any time after that. Some states require a second MMR before a child starts kindergarten.

Adults 18 years or older who were born after 1956 should also receive the MMR vaccine if:

  • They are not sure whether or when they received an MMR
  • They only had one MMR vaccine before starting school

Adults born during or before 1956 are believed to be immune. Many people within that age group had the actual diseases during childhood.

Women of reproductive age who have not received the MMR vaccination in the past should have a blood test to see if they are immune. Being immune means they have had the disease or the vaccine in the past, and are now protected.

If they are not immune, they should receive the MMR vaccine. Women should NOT receive this vaccine if they are pregnant or planning to become pregnant within the next 1 to 3 months. This may harm the baby.


One MMR shot will protect most people from contracting measles, mumps, or rubella throughout their lives. The second MMR shot is recommended to cover people who may not have gotten full protection from the first MMR shot.

Measles is a virusthat causes a rash, cough, runny nose, eye irritation, and fever in most people. It can also lead to pneumonia, seizures, brain damage, and death in some cases.

The mumps virus causes fever, headache, and swollen glands. It can also lead to deafness, meningitis, swollen testicles or ovaries, and death in some cases.

Rubella, also known as the German measles, is generally a mild disease. However, it can cause serious birth defects in the child of a woman who becomes infected while pregnant.


Most people who receive the MMR vaccine will have no problems from it. Others may have minor problems, such as soreness and redness where the shot was given, or fevers. Serious problems from receiving the MMR are rare.

Potential mild to moderate side effects include:

  • Fever (1 in 6 children)
  • Joint pain/stiffness (1 in 4, usually young women)
  • Low platelet count/bleeding (1 in 30,000)
  • Rash (1 in 20)
  • Seizure (1 in 3,000)
  • Swollen glands (rare)

If a rash develops without other symptoms, no treatment is needed. It should go away within several days.

Severe side effects may include:

  • Allergic reaction (less than 1 per million)
  • Long-term seizure, brain damage, or deafness (so rare that the association with the vaccine is questionable)

There is NO evidence linking MMR vaccination with the development of autism.

See also:

  • Immunizations - general overview
  • The Centers for Disease Control and Prevention (CDC) website (

The potential benefits from receiving the MMR vaccine far outweigh the potential risks. Measles, mumps, and rubella are all very serious illnesses. They each can have complications that lead to lifetime disability or even death. For every 1,000 children who get measles, 1 or 2 will die from it.


If the child is ill with something more serious than just a cold, immunization may be delayed. Tell your health care provider if your child had any problems with the first MMR vaccine before scheduling the second one.

The MMR vaccine should not be given to people who have:

  • An allergy to gelatin or the antibiotic neomycin that is serious enough to require medical treatment
  • A weakened immune system due to certain cancers, HIV, steroid drugs, chemotherapy, radiation therapy, or other drugs that suppress the immune system

You should not receive this vaccine if you are pregnant or planning to become pregnant within the next 3 months.

People who have received transfusions or other blood products (including gamma globulin) or who have had low platelet counts should discuss the proper timing of the MMR vaccine with their health care provider.


  • You aren't sure if a person should get, avoid, or delay the MMR vaccine
  • You have moderate or serious symptoms after receiving the vaccine
  • You develop other symptoms that are not common side effects of the MMR vaccine
  • You have any other questions or concerns related to the vaccine


Centers for Disease Control and Prevention. Recommended adult immunization schedule--UnitedStates, 2012. MMWR 2012;61(4).

Centers for Disease Control and Prevention. Recommended immunization schedules for persons aged 0 through 18 years -- United States, 2012, MMWR 2012;61(05):1-4.