The MMR vaccine protects against measles, mumps, and rubella, or MMR. The vaccine typically occurs in two doses during infancy and early childhood. Some adults may need to take the vaccine as well, such as those who travel internationally.

The MMR vaccine is a safe, effective, and affordable vaccine that provides lifelong protection in most people. MMR vaccinations have led to these diseases being much less common in the United States. Side effects are generally mild and severe reactions are typically rare. However, the MMR vaccine may not be suitable for everyone. A person with any concerns should talk with their doctor to discuss all options.

In this article, we discuss the efficacy and safety of the MMR vaccine and suggest who should get it.

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The MMR vaccine provides protection against three diseases:

  • Measles: This is a viral infection that starts with symptoms similar to a cold that progresses to a body rash. It can have serious and life threatening complications, especially in people with weakened immune systems.
  • Mumps: This is a viral infection that generally affects the glands, such as the glands that produce saliva in the neck. It causes other symptoms such as fever and muscle aches, and more serious complications that can affect the reproductive organs, brain, and pancreas.
  • Rubella: Also known as German measles, this is a viral infection that can cause a mild fever and rash in very young children. In adults, it typically results in a mild illness.

The MMR vaccine is a combined live-attenuated vaccine. This means that it contains weakened versions of all three viruses. A combination vaccine merges multiple vaccinations into a single shot, which provides the same protection but requires fewer shots and visits to a doctor.

As a live vaccine, the MMR vaccine uses weakened, or attenuated, forms of the viruses. Because this is similar to the natural infection, the immune system is able to create a strong and long-lasting immune response, which typically provides a person with a lifetime of protection.

In the U.S., people can also receive a MMRV vaccine, which is similar to the MMR vaccine, but also provides protection against varicella, the virus that causes chickenpox. However, the MMRV vaccine is only suitable for children aged 12 months to 12 years.

The MMR vaccine is a very safe and effective vaccine with a low risk for serious complications. However, it is worth noting that all medications, including vaccines, can have side effects. That being said, these side effects are generally mild and much safer than the risks of the diseases themselves. Serious complications are rare but possible, and some groups may be more at risk. If a person has concerns, they can talk with a doctor to discuss the risks.

The MMR vaccine is very effective against measles, mumps, and rubella, as it can prevent the diseases and their complications. The Centers for Disease Control and Prevention (CDC) notes that the suggested MMR vaccination is 97% effective against rubella, 97% effective against measles, and 88% effective against mumps.

Despite being effective, it is still possible for some people who receive two doses of the MMR vaccine to still get the diseases if they encounter the viruses that cause them. However, the disease symptoms are generally milder in vaccinated people.

The availability of these vaccines has greatly reduced the amount of measles, mumps, and rubella cases in the U.S. The widespread use of these vaccines has led to a greater than 99% reduction for both measles and mumps and elimination of rubella in the U.S.

Those who receive MMR vaccinations, as according to the U.S. vaccination schedule, will typically have lifelong protection against rubella and measles. However, it is possible that immunity for mumps may decrease over time, even with a vaccine. Later in life people may need an additional dose if they are at risk for mumps due to an outbreak.

According to recommendations from the CDC, there are a few different groups of people who should get the MMR vaccine.


The CDC recommends all children receive two doses of the MMR vaccine, with the first dose at 12–15 months and the second dose at 4–6 years old. Children can get the second dose earlier, but it must be at least 28 days after the first dose.

Young adults without evidence of immunity

Some educational institutions such as colleges may require students without evidence of immunity to get the MMR vaccine. This may help reduce the chance of an outbreak in areas such as dormitories and halls where many people share spaces.


There are some cases when adults should get the MMR vaccine as well.

Adults who do not have evidence of immunity should get at least one dose, though doctors may recommend two doses for adults that may be in high risk areas for transmission, including:

  • healthcare workers
  • international travelers
  • students or faculty at educational institutions

International travelers

International travelers of all ages should receive protection from measles before any international travel. How this vaccine schedule looks will vary by age. The CDC recommends:

  • Infants from 6–11 months should receive one dose of MMR.
  • Infants who have had their first dose before age 1 and will be traveling should receive two more injections, separated by 28 days.
  • Children from 12 months up should receive two doses of the MMR vaccine, separated by at least 28 days.
  • Teenagers and adults without evidence of immunity should get two doses of MMR separated by 28 days.

The MMR vaccine is safe for most people, and doctors will generally recommend a routine schedule for all vaccinations, including the MMR vaccine.

The CDC recommends two doses of a measles-containing vaccine such as the MMR vaccine for all children. The first dose occurs between 12–15 months old. The second dose can occur 28 days after the first injection, and generally occurs at the ages of 4–6.

It is advisable for older children, teenagers, and adults without evidence of immunity to speak with their doctor and arrange their MMR vaccination as soon as possible.

Who does not need it?

Some people do not need the MMR vaccine. People who have evidence of immunity to these conditions may not require the vaccine. Evidence of immunity may include written documentation of past vaccinations, or evidence from a laboratory that the person has either had the disease or has evidence of immunity in their bodies.

Additionally, people born before 1957 may not need the MMR vaccine, as they will likely have natural immunity from previously having the infections. In some circumstances they may still get it, such as if they work in healthcare.

It may also be advisable for some people not to get the vaccine. This includes:

  • people with severe or life threatening allergies to any part of the vaccine
  • those who are, or think they may be, pregnant
  • people who are immunocompromised or have a family history of immune system complications
  • those with a condition that makes them bruise or bleed easily
  • people with tuberculosis
  • those who recently had a blood transfusion or received other blood products
  • people who have had other vaccines in the past 4 weeks
  • a person who is moderately or severely ill

The CDC notes that most people who get the vaccine do not have serious side effects. Common side effects may include:

  • soreness at the site of the injection
  • fever
  • a mild rash
  • temporary pain and stiffness in the joints

Serious side effects are possible but rare. These may include:

  • a small risk of febrile seizures in infants
  • swelling in the cheeks or neck
  • low platelet count
  • a serious allergic reaction

Anyone who may require the MMR vaccine should discuss their options with their doctor. They may help identify any personal risks or establish immunity before recommending the vaccine. They can schedule an appointment or suggest a local clinic or pharmacy that may hold walk-ins.

The cost of the MMR vaccine may vary by state and the individual pharmacy or clinic administering the vaccine. The CDC lists their cost at about $22 per dose. Pharmacies and clinics may charge around $82 per dose. Some insurance options may be able to provide a lower cost per dose.

The MMR vaccine is a safe and effective vaccine that provides high levels of protection against mumps, measles, and rubella. Doctors may recommend the MMR vaccine as part of a vaccination schedule early in a person’s life. Teenagers and adults may also require the vaccine if they cannot prove immunity.

For most people, the possible side effects are mild and much safer than the diseases themselves. However, the vaccine may not be suitable for everyone. Anyone with concerns or questions should speak with their doctor.