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M-M-R II

Generic name: measles, mumps, and rubella (MMR) vaccine

Last updated November 2, 2026 0 views
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What is the measles, mumps, and rubella vaccine?

Measles, mumps, and rubella are serious illnesses caused by viruses that spread from one person to another.

Getting infected with the rubella virus (also known as German Measles) while pregnant can lead to a miscarriage or severe birth defects.

The M-M-R II is a live virus vaccine designed to help prevent these diseases. This vaccine will not treat any infection you may already have.

The MMR vaccine is given to people who are 12 months old and older. The CDC may suggest an MMR vaccine for some infants aged 6 to 11 months.

Like any vaccine, the MMR vaccine may not protect every person from disease.

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Warnings

You should not receive this vaccine again if you had a life-threatening allergic reaction after a previous dose of this vaccine or any vaccine that contains measles, mumps, and rubella.

This section was rewritten for readability and reviewed for meaning.

Before taking this medicine

You should not get this vaccine again if you had a life-threatening allergic reaction after a previous dose of this vaccine or any vaccine that contains measles, mumps, and rubella, or if you have:

  • a life-threatening allergy to gelatin or neomycin;
  • active untreated tuberculosis; or
  • a weak immune system caused by disease or by using certain medicines, chemotherapy, or radiation.

You can still get the vaccine if you have a minor cold. If you have a more severe illness with a fever or any type of infection, wait until you are better before getting this vaccine.

Your vaccine may need to be delayed or not given at all if you have:

  • an allergy to eggs;
  • seizures, or a family history of seizures;
  • a low blood platelet count or a history of thrombocytopenia;
  • congenital or hereditary immune system problems; or
  • if you have received an immune globulin or a blood or plasma transfusion.

Tell your doctor if you received another live vaccine in the past month or if you plan to receive one. This vaccine may be given at the same time as another live vaccine. If the vaccines are not given at the same time, they should be given 1 month apart.

You should not receive this vaccine if you are pregnant or plan to become pregnant within the next month. Avoid getting pregnant for 1 month after receiving this vaccine.

Ask a doctor if it is safe to breastfeed after receiving this vaccine.

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This vaccine side effects

Get emergency medical help if you notice signs of an allergic reaction: hives, difficulty breathing, swelling of your face, lips, tongue, or throat.

You should not receive the second shot if you had a life-threatening allergic reaction after the first shot.

Keep track of any and all side effects you experience after receiving this vaccine. When you receive a booster dose, you must inform the doctor if the previous shots caused any side effects.

Becoming infected with measles, mumps, or rubella may be more harmful to your health than receiving this vaccine. However, like any medicine, this vaccine can cause side effects, but the risk of serious side effects is extremely low.

Call your doctor immediately if you experience any of these serious side effects:

  • high fever (especially within a few hours or a few days after the vaccine);
  • red, tender bumps under your skin;
  • a light-headed feeling, as if you might faint;
  • easy bruising or bleeding;
  • new or worsening cough, difficulty breathing;
  • problems with balance or muscle movement;
  • a seizure; or
  • severe headache, changes in behavior or consciousness, or trouble walking.

Joint pain or swelling may occur, particularly in teenage girls and adult women. Swelling of the testicles may also happen in men.

Common side effects of M-M-R II may include:

  • fever;
  • rash; or
  • pain at the injection site.

This is not a complete list of side effects, and others may occur. Contact your doctor for medical advice regarding side effects. You can report vaccine side effects to the US Department of Health and Human Services at 1-800-822-7967.

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How is this vaccine given?

Read all vaccine information sheets provided to you.

This vaccine is given as an injection into a muscle or under the skin, usually in a series of 1 to 3 shots. You will receive this injection in a doctor's office or clinic.

This vaccine can cause false results on a skin test for tuberculosis for up to 6 weeks. Tell any doctor who treats you that you have received an MMR vaccine.

In children:

  • The first shot is usually given at 12 to 15 months of age. The second dose is usually given at 4 to 6 years of age, or before the child starts elementary school.
  • The CDC recommends an MMR vaccine for infants 6 to 11 months old who will be traveling outside the United States.
  • A child who has received this vaccine before 12 months of age should still receive an MMR vaccine at age 12 to 15 months, followed by a booster shot at the recommended ages of 4 to 6 years for long-lasting protection.

In adults:

  • Adults may need 1 or 2 doses of MMR vaccine, depending on their risk. Follow your doctor's instructions or the schedule recommended by your local health department.

Where there has been a measles outbreak, local health departments may recommend 1 or 2 doses of MMR vaccine for children as young as 6 months old, and for older children and adults who are not already immune to measles, mumps, and rubella.

If you have been exposed to measles, MMR vaccine may be given within 72 hours after exposure. During a mumps outbreak, a third dose of MMR vaccine may be recommended for some people at increased risk.

Your booster schedule may be different from these guidelines. Follow your doctor's instructions or the schedule recommended by your local health department.

What happens if I miss a dose?

Call your doctor if you will miss a booster dose or if you get behind schedule. The next dose should be given as soon as possible. There is no need to start over.

  • Be sure to receive all recommended doses of this vaccine or you may not be fully protected against infection.

This section was rewritten for readability and reviewed for meaning.

What happens if I overdose?

An overdose of this vaccine is unlikely to happen.

Follow your doctor's instructions regarding any limits on food, drinks, or activities.

This section was rewritten for readability and reviewed for meaning.

What other drugs will affect this vaccine?

Before getting this vaccine, inform your vaccination provider about all other vaccines you have recently had.

Let the vaccination provider know if you have recently taken any medications or treatments that can weaken your immune system, such as:

  • steroid medicine;
  • chemotherapy or radiation treatments;
  • medications for psoriasis, rheumatoid arthritis, or other autoimmune disorders; or
  • medicines to treat or prevent organ transplant rejection.

Other medicines may impact this vaccine, including prescription and over-the-counter drugs, vitamins, and herbal products. Inform your doctor about all other medicines you are using.

This section was rewritten for readability and reviewed for meaning.

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.