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M-M-R II Vaccine

Generic name: measles, mumps, and rubella virus vaccine live

What is M-M-R II Vaccine?

M-M-R II is also known as Measles, Mumps, and Rubella Virus Vaccine Live, or MMR Vaccine. It is a live virus vaccine that is given as a shot. This vaccine is usually given to people one year old or older. It is meant to help prevent measles (rubeola), mumps, and rubella (German measles).

M-M-R II contains weakened forms of measles virus, mumps virus, and rubella virus.

How does the M-M-R II Vaccine work?

M-M-R II works by helping the immune system protect you or your child from getting measles, mumps, or rubella.

M-M-R II may not protect everyone who gets the vaccine. M-M-R II does not treat measles, mumps, or rubella once you or your child has them.

What do I need to know about measles, mumps, and rubella?

Measles is also known as rubeola. It is a serious illness. Measles virus can be passed to others if you have it. Measles can give you a high fever, cough, and a rash. The illness can last for 1 to 2 weeks. In rare cases, it can also cause an infection of the brain. This could lead to seizures, hearing loss, intellectual disability, and even death.

Mumps can also be passed to others. This virus can cause fever and headache. It can also make the glands under your jaw swell and be painful. The illness often lasts for several days. Sometimes, mumps can make the testicles swell and be painful. In some cases, it can cause meningitis, which is a swelling of the coverings of the brain and spinal cord.

Rubella is also known as German measles. It is often a mild illness. Rubella virus can cause a mild fever, swollen glands in the neck, pain and swelling in the joints, and a rash that lasts for a short time. It can be very dangerous if a pregnant woman catches it. Women who catch German measles when they are pregnant can have babies who are stillborn. Also, the babies may be blind or deaf, or have heart disease or intellectual disability.

Who should not take M-M-R II Vaccine?

Do not get M-M-R II if you or your child:

  • are allergic to any of its ingredients. (This includes gelatin. See the ingredient list at the end of this guide.)
  • have a weakened immune system (which includes taking high doses of steroids by mouth or in a shot).
  • have a fever.
  • have active tuberculosis that is not treated.
  • are pregnant or plan to get pregnant within the next month.

What should I tell my healthcare provider before taking M-M-R II Vaccine?

Tell your health care provider if you or your child:

  • have or have had any medical problems.
  • have a history of seizures or someone in your family has a history of seizures.
  • have received blood or plasma transfusions or human serum globulin.
  • take any medicines. (This includes non-prescription medicines and dietary supplements.)
  • have any allergies.
  • had an allergic reaction to any other vaccine.
  • have or have had a low blood platelet count.
  • are allergic to eggs.

How should I take M-M-R II Vaccine?

M-M-R II is given as a shot to people one year old or older. The dose of the vaccine is the same for everyone. If your child gets the shot when he or she is one year old or older, a second dose is recommended. Often, the second dose is given right before the child goes to elementary school (4 to 6 years of age), but may be given earlier as long as the second dose is at least one month after the first dose.

If your child is less than one year old when he or she first gets the shot, a second dose should be given when they are 12 to 15 months old. Then, a third shot should be given between 4 and 6 years of age. Your doctor will decide the best time and number of shots by using official recommendations.

If a dose is missed, your health care provider will let you know when you should have it.

What are the possible side effects of M-M-R II Vaccine?

The most common side effect of vaccination with M-M-R II is pain at the site of the shot for a short time.

Other side effects may include:

  • Fever
  • Rash

Less common side effects may also include:

  • Swelling of the testicles
  • Joint pain and/or swelling

Some side effects are rare but may be serious. You should call your health care provider if you notice any of the following problems:

  • Difficulty breathing, wheezing, hives, or a skin rash may be signs of an allergic reaction
  • Bleeding or bruising under the skin
  • Seizures, a severe headache, a change in behavior or consciousness, or difficulty walking

Other side effects may also occur. Your doctor has a more complete list of side effects for M-M-R II.

Contact your doctor or health care provider if you or your child have any new or unusual symptoms after receiving M-M-R II.

Report the following to your doctor or your child’s doctor:

  • exposure to M-M-R II during pregnancy
  • exposure to M-M-R II during the month before getting pregnant

You may also report any adverse reactions to your doctor or your child's health care provider or submit a report directly to the Vaccine Adverse Event Reporting System (VAERS). The VAERS toll-free number is 1-800-822-7967 or you may report online to

General information about the safe and effective use of M-M-R II Vaccine

This guide summarizes important information about M-M-R II.

If you would like more information, talk to your health care provider or call 1-800-622-4477.

What are the ingredients in M-M-R II Vaccine?

Active Ingredients: weakened forms of the measles, mumps, and rubella viruses.

Inactive Ingredients: sorbitol, sucrose, hydrolyzed gelatin, recombinant human albumin, fetal bovine serum, other buffer and media ingredients, neomycin.

Source: National Library of Medicine. Last updated June 30, 2020.