Over the years, scientists have developed highly effective vaccines that have significantly reduced and prevented the spread of highly contagious diseases worldwide. One such vaccine is the measles, mumps and rubella (MMR) vaccine.

Below, we’ll explain what the MMR vaccine is and what it protects against. We’ll also go over the MMR vaccine schedule for children and adults, possible side effects and why it’s so important to get vaccinated.

Why is it important to get the MMR vaccine? It saves lives.

When the MMR vaccine is widely used, it prevents diseases like measles from spreading in our communities. Because of vaccination, measles was declared eliminated in the United States in 2000, meaning the disease was no longer spreading continuously within the country.

But the U.S. has experienced a growing number of measles outbreaks, with thousands of reported cases. Most infections have occurred among people who aren't protected through vaccination.

Measles can cause serious complications and can be especially dangerous for babies, young children and people with weakened immune systems. It can lead to complications such as pneumonia and encephalitis (swelling of the brain).

Data shows that about 1 in 5 unvaccinated people who get measles will be hospitalized, and about 1 to 3 people out of every 1,000 who get measles will die from complications.

That’s why the MMR vaccine so important: It can help prevent the spread of a serious illness and help keep you, your family and your community safe.

What is the MMR vaccine and how does it work?

The MMR vaccine is a live-attenuated vaccine, which means it contains a small amount of weakened measles, mumps and rubella (German measles) viruses. The first vaccines to protect against measles, mumps and rubella were developed in the 1960s and given as individual shots. Then in the 1970s, scientists introduced a combined MMR vaccine to protect against all three diseases.

Today, there are two MMR vaccine formulations:

  • MMR vaccine – Protects against measles, mumps and rubella
  • MMRV vaccine – Protects against measles, mumps, rubella and varicella (chicken pox), and it’s only approved for use in children 12 months to 12 years old

At HealthPartners, we generally recommend the MMR vaccine because the MMRV vaccine has been associated with a slightly higher risk for fever and febrile seizures after vaccination. There’s a separate vaccination for protection from varicella.

HealthPartners bases vaccine recommendations on the latest scientific evidence about vaccine safety and effectiveness. In alignment with state health departments, we follow the recommendations of the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP) and other organizations recognized for their medical expertise.

How the MMR vaccine works

Like all vaccines, the MMR vaccine activates your immune system and teaches it how to fight certain germs without you getting sick. Despite some vaccine myths, a live-attenuated vaccine can’t give you any of the diseases it protects against. Most people receive two doses of the MMR vaccine, which maximizes long-term immunity.

How effective the MMR vaccine is at preventing illness

According to the Centers for Disease Control and Prevention (CDC), one dose of the MMR vaccine is:

  • 93% effective against measles
  • 72% effective against mumps
  • 97% effective against rubella

Two doses of the MMR vaccine is:

  • 97% effective against measles
  • 86% effective against mumps

Because rubella was declared eliminated in the U.S. in 2004, there aren’t many studies available about how effective a second dose of MMR is at protecting against rubella.

While it is still possible to contract measles, mumps and rubella from an infected person even if you’re vaccinated against them, it’s extremely rare. And if you do get any of the diseases, it likely won’t be a serious case or cause serious complications.

How long does the MMR vaccine protect you?

If you’ve received the full vaccine schedule, you’re considered protected for life against measles and rubella, and probably wouldn’t contract either infection if exposed to it. While the MMR vaccine provides highly effective protection against mumps, studies have shown that your immunity may decrease over time, and you may not be protected against mumps if you’re exposed to it later in life.

How safe is the MMR vaccine?

The benefits of the MMR vaccine greatly outweigh the risks associated with contracting measles, mumps or rubella.

The MMR vaccine has been tested rigorously worldwide, administered to millions of people and proven to be safe. It’s the most effective way to protect yourself and your children against illness and serious complications from preventable diseases.

The MMR vaccine cannot cause autism

Autism spectrum disorder (ASD) is a developmental disorder that continues to be studied extensively. In these studies, it’s been determined that there is no link between receiving vaccinations and developing ASD. Additionally, there aren’t any links found between the ingredients in vaccines and ASD.

The MMR and other vaccines do not increase the risk of developing autism, and do not trigger autism in children. The typical side effects are rare and mild, and it’s much safer to get the vaccine than risk potential illness.

Who should get the MMR vaccine and when

The MMR vaccine is a part of the recommended vaccine schedule for children, and it’s a safe and effective way to protect against highly contagious measles, mumps and rubella infections.

HealthPartners recommends that everyone get the MMR vaccine if they’re able to, but the recommendations for what vaccine to get and when are different for adults, teens and children.

It’s important to keep your child current on their vaccination schedule to protect them against preventable illnesses. Recommended timing for the MMR vaccine is:

  • The first dose when your child is 12 to 15 months old
  • The second dose when your child is 4 to 6 years old

Under special circumstances, it’s possible for your child to get their second dose earlier, as long as it’s given at least 28 days after their first. If your child is traveling internationally, or if there is a local outbreak of measles or mumps in your community, HealthPartners recommends following the minimum interval of 28 days.

For children ages 12 months to 4 years old, the MMR and MMRV vaccines are both options, but speak with your doctor about which vaccine is right for your child.

For children who are 4 years old and older, both MMR and MMRV are options. HealthPartners recommends that:

  • If MMR is given as a first dose, the preferred second dose is MMRV
  • If MMRV is given as a first dose, MMRV is the preferred second dose over separate MMR and varicella vaccines

If your child gets MMRV as their first vaccine, they should receive the second MMRV vaccine at least three months after the first.

MMR vaccine schedule for teens

For teens older than 12 years old who have received both doses of MMR, there’s no need for additional doses.

For teens older than 12 years old who weren’t vaccinated as children, HealthPartners recommends both MMR doses, at least 28 days apart.

For teens who are going into post-high school institutions, like a college or university, many vaccines may be required, including the MMR vaccine. If they didn’t receive the vaccine when they were younger, it’s recommended they get both MMR doses, at least 28 days apart. Once they’ve received both doses, there’s no need for a booster.

MMR vaccine schedule for adults

Adults who can show immunity to measles, mumps and rubella, because they’ve either been fully vaccinated or they had measles, mumps and rubella at some point in their lives, do not need an MMR vaccine dose at any time.

Adults who didn’t have measles, mumps or rubella at any point in their lives or are unsure if they’re fully vaccinated should receive at least one dose of the MMR vaccine. Certain adults at greater risk of measles and mumps may need two doses at least 28 days apart if:

  • They’re a student, faculty member or part of the staff at a post-high school institution
  • They work in a health care setting
  • They’re traveling internationally

Possible side effects of the MMR vaccine

Most people don’t experience side effects from the MMR vaccine, but if they do, side effects are usually mild. If you do experience these mild side effects, it’s a sign from your immune system that the vaccine is working. Side effects can include:

  • Fever
  • Mild rash
  • Pain at the injection site
  • Temporary stiffness or pain in the joints, particularly in teens and adult women who didn’t already have immunity to the rubella part of the vaccine
  • Swelling in the cheeks or neck (very rare)
  • Low platelet count (very rare)

Extremely rarely, a person might have a serious allergic reaction to the MMR vaccine. If you do experience a serious reaction, like anaphylaxis or difficulty breathing, call 911 immediately.

The MMRV vaccine has been linked to a very small risk of febrile seizures, which are seizures caused by a fever, but it’s extremely rare and doesn’t cause long-term side effects.

Since the risk of febrile seizures increases as children get older, it’s recommended they follow the MMR vaccine schedule and get vaccinated as soon as they’re able.

And finally, if you have an allergic reaction to any component of the vaccine, or a serious allergic reaction to the antibiotic neomycin (which is in the vaccine), you should not get the vaccine.

Protect yourself from measles, mumps and rubella

Vaccines like the MMR vaccine offer the best protection against highly contagious yet preventable diseases, so speak with your doctor to determine if or when you or your child should receive it.

If you know you or your child hasn’t been vaccinated against MMR, or if you’re unsure of your MMR vaccination status, speak to your doctor about next steps. And if your child is due for their MMR shot, make an appointment to get the vaccine. It’s important for your child’s health to be up to date on all recommended vaccinations.