The MMR vaccine is the main way to prevent measles

The measles, mumps, and rubella (MMR) vaccine is the most effective way to prevent measles. Two doses of the MMR vaccine protect about 97 percent of people who receive them. The vaccine works by teaching your immune system to recognize and fight the measles virus before you encounter it in the real world.

Most children in the United States receive their first MMR dose at 12 to 15 months old and their second dose at 4 to 6 years old. If you were born in 1957 or later and have not been vaccinated, or if you are unsure of your vaccination status, you can receive the vaccine at any age. Adults who travel internationally, work in healthcare, or live in areas with measles cases should make sure they have both doses.

The vaccine is given as a single shot and causes mild side effects in some people—arm soreness, low fever, or a light rash a week or two later. Serious side effects are extremely rare. If you have questions about whether the vaccine is right for you or your child, your doctor can review your health history and advise you.

Key Takeaways

  • Two doses of the MMR vaccine protect about 97 percent of vaccinated people from measles infection.
  • Children typically receive the first dose at 12 to 15 months old and the second dose at 4 to 6 years old.
  • Adults born in 1957 or later who are unsure of their vaccination status should contact their doctor to check their records and receive any needed doses.
  • If you cannot be vaccinated for medical reasons, staying away from people with measles and avoiding travel to countries with active measles cases reduces your risk.
  • Measles spreads through the air, so vaccination protects not only you but also people around you who cannot be vaccinated.

Who should get the MMR vaccine and when

The standard schedule calls for the first MMR dose at 12 to 15 months and the second at 4 to 6 years. However, the timing can shift based on your situation. Infants traveling internationally can receive a dose as early as 6 to 11 months, followed by the standard two-dose series later. Children in childcare or preschool may be vaccinated earlier if there is a measles outbreak in your area.

Adults who were born in 1957 or later should have received two doses. If you were born before 1957, one dose is generally considered sufficient because measles was common and most people were naturally infected. If you are unsure whether you were vaccinated, your doctor can check your vaccination records or run a blood test to see if you have immunity.

Some people cannot receive the MMR vaccine for medical reasons—for example, people with certain immune system disorders or severe allergies to vaccine ingredients. Pregnant people should not receive the vaccine, though they can receive it after delivery. If you fall into one of these groups, talk with your doctor about other ways to reduce your measles risk.

What to do if you have been exposed to measles

If you have been around someone with measles and you are not vaccinated or unsure of your vaccination status, contact your doctor right away. The MMR vaccine can prevent measles or reduce how severe it is if given within 72 hours of exposure. This window is narrow, so call your doctor or local health department the same day you learn of the exposure.

If you cannot receive the vaccine—because you are pregnant, immunocompromised, or allergic to it—your doctor may recommend an injection called immune globulin, which can reduce your risk if given within 6 days of exposure. This is not a vaccine but rather antibodies that help your body fight the virus.

While waiting to see your doctor or after exposure, avoid contact with other people, especially infants, pregnant people, and anyone with a weakened immune system. Measles spreads through the air when an infected person coughs or sneezes, so staying home protects others around you.

Vaccination records and proof of immunity

Keep a copy of your vaccination records in a safe place. Your doctor's office, school records, or your state health department can provide a copy if you have lost yours. Some workplaces, schools, and travel destinations require proof of MMR vaccination, so having documentation on hand saves time.

If you cannot find your records and do not remember whether you were vaccinated, your doctor can order a blood test to check for immunity to measles. This test, called a titer, shows whether your body has antibodies against the virus. If the test shows you are not immune, you can receive the vaccine.

Some states allow you to request your vaccination records online through your health department's website. Others require a phone call or in-person visit. Starting this process early—before you need the records for travel or a job—prevents delays.

Measles outbreaks and community protection

When a large percentage of a community is vaccinated, measles cannot spread easily from person to person. This is called herd immunity. If about 95 percent of people in an area are vaccinated, the virus dies out because it cannot find enough unvaccinated people to infect. This protects people who cannot be vaccinated, including newborns too young for their first dose and people with certain medical conditions.

When vaccination rates drop below this threshold, measles can spread rapidly. Outbreaks have occurred in communities where vaccination rates fell to 85 percent or lower. If you live in or travel to an area with a measles outbreak, vaccination becomes even more important for your protection and the protection of those around you.

You can check whether measles is circulating in your area by visiting your state or local health department's website. They post updates about confirmed cases and outbreaks. If measles is present in your community and you are not vaccinated, contact your doctor to discuss your options.

Other steps to reduce measles risk

Vaccination is the most reliable prevention, but other steps can lower your risk if you cannot be vaccinated or are waiting for your appointment. Wash your hands frequently with soap and water, especially after being in public spaces or around people who are sick. Measles spreads through respiratory droplets, so hand hygiene reduces transmission if you touch your face after exposure.

If you are traveling to a country where measles is common, check your vaccination status before you go. Many countries in Africa, Asia, and the Pacific region have higher measles rates than the United States. Your doctor can advise you on vaccination timing if you are planning international travel.

If you are around someone with measles symptoms—high fever, cough, runny nose, and the characteristic rash—ask them to wear a mask and maintain distance. If you are the one with symptoms, wear a mask around others and stay home until you have been fever-free for at least three days without fever-reducing medicine.

Frequently Asked Questions

Can I get measles if I have been vaccinated?

It is very rare. Two doses of the MMR vaccine protect about 97 percent of people. The remaining 3 percent may still catch measles, but their illness is usually much milder than in unvaccinated people. If you have received two doses and are still concerned, a blood test can confirm whether you have immunity.

Is the MMR vaccine safe?

Yes. The MMR vaccine has been used for decades and has been studied extensively. Common side effects are mild—arm soreness, low fever, or a temporary rash. Serious side effects are extremely rare. Your doctor can discuss any specific health concerns you have before vaccination.

What if I was vaccinated as a child but do not have records?

Contact your childhood doctor's office, your school, or your state health department to request copies of your records. If records cannot be found, a blood test can show whether you have immunity. If you are not immune, you can receive the vaccine again—getting vaccinated twice if you were already vaccinated is safe.

Do I need the MMR vaccine if I had measles as a child?

No. If you had measles, your body developed natural immunity and you cannot catch it again. However, if you are unsure whether you actually had measles or just think you did, a blood test can confirm immunity. Natural immunity is lifelong.

Can pregnant people receive the MMR vaccine?

No, the MMR vaccine should not be given during pregnancy because it is a live vaccine. However, pregnant people can receive the vaccine after delivery, even while breastfeeding. If you are planning to become pregnant and are unsure of your vaccination status, talk with your doctor about getting vaccinated before conception.