The MMR vaccine protects against measles, mumps, and rubella. (Rubella is also called German measles). Many children in the U.S. are immunized as infants and toddlers. But not everyone gets vaccinated as a child. Many adults move to the U.S. from countries without immunization programs. World travel increases the chances of these diseases spreading.
Adults who were born before 1957 are usually immune to (protected against) measles, mumps, and rubella. This is because most people got these diseases as children before vaccines were available. If you were born in 1957 or after, The CDC recommends that you get the MMR vaccine unless you have:
- Lab results showing that you're immune to all three diseases
- Medical records showing you've had all three diseases
- Proof that you've been vaccinated for all three diseases, whether you were vaccinated as a child or after
Why Do Adults Need the MMR Vaccine?
The three diseases covered by the MMR vaccine are highly contagious. Viruses cause all three of these illnesses, and they spread through the air. They can pass from person to person through coughing, sneezing, or just breathing.
Measles. This disease causes a fever, runny nose, rash, and in severe cases, hospitalization, pneumonia, encephalitis, or death. It attacks your throat and lungs. Vaccinations have helped stop the spread of measles in the U.S., but there are still cases reported. While immunization rates are on the rise around the world, the World Health Organization (WHO) estimates there were 207,500 measles deaths in 2019. Measles outbreaks often happen in countries without strong childhood immunization programs. But outbreaks have also happened in Europe, South Africa, and the Philippines.
Mumps. This disease causes fever, fatigue, head and muscle aches, and swelling of your salivary glands. In men, it can cause the testicles to become inflamed. Mumps can lead to a loss of hearing, infection of the covering around your brain and spinal cord, and other serious problems. Mumps outbreaks do still happen in the U.S., but rarely.
Rubella (German measles). This disease can cause a fever and rash. It's especially dangerous if you're pregnant. Rubella can lead to serious birth defects, including heart problems, deafness, liver and spleen damage, and mental disability. If you have rubella while pregnant, there's at least a 20% chance your baby will have health problems.
When Should Adults Get the MMR Vaccine?
The CDC says most adults born in 1957 or later should get at least one dose of the MMR vaccine. All women of childbearing age should get the MMR vaccine unless they're pregnant, have proof of immunity, or proof of already being vaccinated.
Measles Booster
The CDC says adults at greater risk of measles or mumps should get two doses of MMR vaccine, the second one four weeks after the first. This includes adults who:
- Have been exposed to measles or mumps or live in an area where an outbreak has happened
- Are students in colleges or trade schools
- Travel internationally
- Work in health care
For measles, the CDC advises a second dose for adults who:
- Were previously given a vaccine made with "killed" measles instead of the live, attenuated (weakened) vaccine used today
- Were given an MMR vaccine between 1963 and 1967 but there's no record of what type.
If you were born before 1957 but can't show proof that you're immune to or had measles, mumps, and rubella, it's best to get the MMR vaccine. If you're a health care professional born before 1957 and you don't have proof or immunity or disease, you should get two doses of the MMR vaccine, given at least 28 days apart.
Exceptions: Who Does Not Need the MMR Vaccine?
Adults don't need the MMR vaccine if:
- They have proof of vaccination already.
- They have proof that they've already had measles or mumps and rubella.
Who Should Not Have the MMR Vaccine?
Adults who shouldn't get the MMR vaccine include people in these groups:
Pregnancy. If you're pregnant, you shouldn't get the MMR vaccine because of risks to your baby. People who get the MMR vaccine should wait four weeks before getting pregnant.
Life-threatening allergic reactions. Adults who have had a life-threatening allergic reaction to gelatin, a previous MMR vaccine, or a medication called neomycin shouldn't get the vaccine.
Medical conditions. Adults should talk with their doctor if they:
What Are the MMR Vaccine Ingredients?
As with many vaccines, the MMR vaccine works with your immune system to build up protection by putting a small amount of the weakened virus into your body. The safest and most effective ingredients in the MMR vaccine used today include "attenuated" forms of each virus. This means they're live forms of the virus that have been made weak in medical labs.
What Are the Risks and Side Effects of the MMR Vaccine?
For most adults, the benefits of the MMR vaccine outweigh the risks. A few people develop a short-term mild rash, fever, swollen glands, or pain and stiffness in their joints after getting the shot. More serious and rare side effects include a temporarily low platelet count or serious allergic reaction.
Call your doctor if you have trouble breathing, dizziness, rapid heartbeat, hives, weakness, or other problems after vaccination.
