MMR Vaccine (Measles-Mumps-Rubella): What You Should Know

The introduction and distribution of the MMR (measles-mumps-rubella) vaccine in the United States changed the trajectory of these diseases. Illnesses that were commonplace among baby boomers now occur very rarely. Still, vaccination is the best way to protect yourself and the people around you from measles, mumps, and rubella and to maintain the rarity of these diseases in the U.S.

This article provides an overview of the MMR vaccine, describes symptoms and complications of measles, mumps, and rubella, and outlines who should and should not get the MMR vaccine.

Doctor vaccinating girl in office

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What Is the MMR Vaccine?

The MMR vaccine protects people from measles, mumps, and rubella. It is a two-dose regimen that is typically recommended to start in early childhood. It is extremely effective at protecting against infection and severe illness.


Measles is a highly contagious disease that is characterized by:

  • Rash
  • Fever
  • Cough
  • Runny nose
  • Red, watery eyes

Although the symptoms of measles may seem mild, they can be fatal, especially in children.

One 2020 study on the reemergence of measles found that 350,000 cases of measles were reported worldwide in 2018, with 142,300 resulting in death. The majority of deaths occurred in adults with a weakened immune system or in children under 5 years old.


Mumps is a viral illness that causes the salivary glands to swell, creating the appearance of puffy cheeks. The swelling is often accompanied by:

More severe complications of mumps include inflammation of the testicles, ovaries, pancreas, brain, or the tissues covering the spinal cord, as well as deafness (in rare cases).

Mumps Complications Prior to Vaccine Availability

Before the MMR vaccine was available, mumps was the leading cause of meningitis (an inflammation of the brain and spinal cord) and hearing loss in children, as well as hospitalization among military personnel. The introduction of the two-dose MMR vaccine reduced cases of mumps by 99%, thus reducing negative outcomes.


Rubella is a disease that shows up as a rash on the face and spreads to the rest of the body over the course of three days, on average. Other symptoms of rubella include:

However, in 25%–50% of rubella cases, people don't have any symptoms at all.

Rubella can come with complications, like heart and bleeding problems.

Those most at risk are developing babies during pregnancy. If a pregnant woman who has not received the MMR vaccine contracts the illness, she is at a greater risk for miscarriage or stillbirth. A baby that does survive is at a higher risk of developing heart problems, loss of hearing or eyesight, intellectual disability, or liver or spleen damage.

Who Should Get the MMR Vaccine?

The MMR vaccine is recommended for all children, with the first dose occurring between 12 months and 15 months. The second dose should be administered between ages 4 and 6.

People who didn't receive the MMR vaccine in childhood can get it as an adult. Two doses are still recommended and should be separated by at least 28 days.

Who Should Not Get the MMR Vaccine?

According to the Centers for Disease Control and Prevention (CDC), there are certain people who should not get the MMR vaccine. These include people who:

  • Have severe or life-threatening allergies, or who have had a severe allergic reaction to a dose of the MMR vaccine in the past
  • Are pregnant or may be pregnant
  • Have a compromised or weakened immune system
  • Have an immediate family member with immune system problems
  • Have a condition that causes them to bleed or bruise easily
  • Have tuberculosis (contagious infection that affects the lungs)


The MMR vaccine is extremely effective. It offers 97% protection against measles and rubella and 88% against mumps in people who have received two doses of the vaccine.

One study looking at the effectiveness of the MMR vaccine in preventing hospitalizations found that no child who had received two doses of the vaccine was hospitalized for rubella or measles and only one fully vaccinated child was hospitalized for mumps.

Risk and Side Effects

In addition to being effective, the MMR vaccine is also safe.

As with most vaccines or medications, there are risks and side effects that can occur. According to the CDC, the most common side effects are:

  • Soreness at the injection site
  • Fever
  • Mild rash
  • Temporary joint pain or stiffness

More serious side effects can occur, so talk to your healthcare provider if you have concerns.

Allergic Reactions

If you have a severe allergic reaction to the MMR vaccine, call 911 and go to the nearest hospital.


Measles, mumps, and rubella are serious illnesses that can lead to lifelong health problems and, in some cases, even death. Vaccination against MMR is the best strategy to avoid the long-term consequences of these diseases. The MMR vaccine has proven to be safe and effective.

MMR vaccines are recommended in childhood with a two-dose series, but adults who have not received theirs are eligible and encouraged to get vaccinated.

A Word From Verywell

Vaccination is the best tool to protect your child from measles, mumps, and rubella, all of which can be dangerous. Talk to your child's healthcare provider about the benefits of vaccination and any side effects you should be aware of. MMR vaccination will not only help protect your child but also those around them.

Frequently Asked Questions

  • How long does a fever after the MMR vaccine last?

    A fever from the MMR vaccine occurs most commonly between day seven and day 12 after receiving the injection, and typically lasts one or two days.

  • Should you get vaccinated after being exposed to measles, mumps, and rubella?

    If you do not have immunity against measles, mumps, and rubella, getting the vaccine within 72 hours of a measles exposure could provide some protection and help to reduce the severity of the illness. This is only true for measles; getting the MMR vaccine after being exposed to mumps or rubella does not have the same protective effects.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Measles, mumps, rubella (mmr) vaccine.

  2. Misin A, Antonello RM, Di Bella S, et al. Measles: An overview of a re-emerging disease in children and immunocompromised patients. Microorganisms. 2020;8(2):276. doi:10.3390/microorganisms8020276

  3. Centers for Disease Control and Prevention. Signs and symptoms of mumps.

  4. Centers for Disease Control and Prevention. Mumps complications.

  5. Centers for Disease Control and Prevention. Epidemiology and prevention of vaccine-preventable diseases.

  6. Centers for Disease Control and Prevention. Rubella signs and symptoms.

  7. Centers for Disease Control and Prevention. Rubella complications.

  8. Centers for Disease Control and Prevention. Measles, mumps and rubella vaccination: what everyone should know.

  9. La Torre G, Saulle R, Unim B, et al. The effectiveness of measles-mumps-rubella (MMR) vaccination in the prevention of pediatric hospitalizations for targeted and untargeted infections: A retrospective cohort studyHum Vaccin Immunother. 2017;13(8):1879-1883. doi:10.1080/21645515.2017.1330733

  10. World Health Organization. Information sheet - observed rate of vaccine reactions measles, mumps and rubella vaccines.

By Teresa Maalouf, MPH
Teresa Maalouf is a public health professional with six years of experience in the field. She has worked in research, tobacco treatment, and infectious disease surveillance. Teresa is focused on presenting evidence-based health information in a way that is clear and approachable.