Over the years, scientists have developed groundbreaking 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. In fact, the MMR vaccine is the reason why measles, mumps and rubella are much less common in the United States today.
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.
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
The MMR vaccine is the recommended formulation by the Centers for Disease Control and Prevention (CDC) 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.
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 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 eradicated 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.
Why it’s important to get the MMR vaccine
As with any vaccine, the benefits of the MMR vaccine greatly outweigh the risks associated with contracting measles, mumps or rubella.
For example, before the national measles vaccination program began in the U.S. in the 1960s, nearly every person had measles before adulthood, with around half a million reported cases per year. Most people who had it recovered without long-term side effects. But others experienced long-term side effects or had to be hospitalized, and many died from complications of the disease.
Due to the success of the vaccine program, measles was declared eradicated in the U.S. by the year 2000. Deaths due to complications from measles dropped from around 500 each year to three recorded cases from 2000-2024. However, scientists have seen outbreaks of measles cases in the U.S. in recent years due to a number of factors, the biggest being vaccine hesitancy.
Data shows that about 1 in 5 unvaccinated people will need to be hospitalized if they contract measles. In addition, measles can lead to more severe issues such as pneumonia and encephalitis (swelling in the brain), and statistics have shown that 3 people out of 1,000 will die, even with the best care possible. So, it’s important to get the vaccine to protect yourself from preventable illness.
And while there has been an over 99% decrease in reported mumps and rubella cases since the 1960s due to the MMR vaccine, outbreaks can still occur, so it’s still a crucial part of the vaccine to keep you safe.
How safe is the MMR vaccine?
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.
While many people recover, others can experience complications from these viral infections that range from mild to life threatening.
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.
The CDC 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. The MMR vaccine is part of that schedule, and the CDC recommends:
- 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, the CDC 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 and older, both MMR and MMRV are options. The CDC 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, the CDC 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
The CDC and most medical professionals recommend getting the MMR vaccine. 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 haven’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.
