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.



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

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:

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 providers 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
  • Other symptoms that are not common side effects of the MMR vaccine develop
  • You have any other questions or concerns related to the vaccine

Alternative Names

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


Centers for Disease Control and Prevention. 2012 immunization schedules for children 0 to 18 years of age. October 25, 2011.

Centers for Disease Control and Prevention. 2011 adult immunization schedule. United States. 2011. Proposed Revisions. Advisory Committee on Immunization Practices. October 28, 2010.

Coonrod DV, Jack BW, Boggess KA. The clinical content of preconception care: immunizations as part of preconception care. Am J Obstet Gynecol. 2008;199:S290-S295.

Updated: 4/15/2012

Reviewed by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

Notice: The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2012, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.