Yes, there is a measles vaccine, and it's highly effective

The measles vaccine exists and has been available for decades. It's given as part of the MMR vaccine, which protects against three diseases: measles, mumps, and rubella. The vaccine works by teaching your immune system to recognize and fight measles without you having to get the disease itself.

The MMR vaccine is one of the most effective vaccines available. After two doses, it prevents measles in about 97 out of 100 people who receive it. A single dose protects roughly 93 out of 100 people. This high protection rate is why measles, which once killed hundreds of children each year in the United States, is now rare in vaccinated populations.

Key Takeaways

  • The MMR vaccine protects against measles, mumps, and rubella, and two doses prevent measles in about 97 out of 100 vaccinated people.
  • Children typically receive their first MMR dose at 12 to 15 months old and a second dose between 4 and 6 years old.
  • The vaccine is a live attenuated vaccine, meaning it contains a weakened form of the virus that cannot cause measles disease.
  • Common side effects are mild and temporary, such as soreness at the injection site or a low fever a week or two after vaccination.
  • If you're unsure whether you've been vaccinated, your doctor can test your immunity with a simple blood test.

How the measles vaccine is given

The MMR vaccine is an injection, usually given in the arm. It's a live attenuated vaccine, which means it contains a weakened form of the measles virus. This weakened virus is strong enough to teach your immune system how to fight measles, but too weak to cause the actual disease in healthy people.

The standard schedule calls for the first dose at 12 to 15 months of age and a second dose between 4 and 6 years old. Some situations call for a different timing—for example, if you're traveling internationally or if there's an outbreak, your doctor may recommend the first dose as early as 9 months. Adults who were never vaccinated or whose vaccination status is unknown can receive the vaccine at any age.

Who should and shouldn't get the measles vaccine

Most children and adults should receive the MMR vaccine. It's part of the routine childhood vaccination schedule in the United States and is required for school attendance in all 50 states, though medical and religious exemptions exist depending on your state.

Certain people should not receive the MMR vaccine. These include people with severe allergies to any component of the vaccine, people with untreated tuberculosis, and people with severely weakened immune systems due to conditions like advanced HIV or certain cancers. Pregnant people should not receive the vaccine, though they can receive it after giving birth. If you have questions about whether the vaccine is right for you or your child, your doctor can review your medical history and advise you.

What to expect after vaccination

Most people have no side effects from the MMR vaccine. When side effects do occur, they are usually mild. Common reactions include soreness, redness, or swelling at the injection site, and a low fever or mild rash that appears 7 to 14 days after the shot. These reactions show that your immune system is responding to the vaccine and typically resolve on their own within a few days.

Serious side effects are very rare. Severe allergic reactions happen in fewer than one per million doses. Your doctor or nurse will ask you to wait 15 minutes after vaccination so they can monitor you in case an immediate reaction occurs, though this is uncommon.

Vaccine protection and immunity

After two doses of the MMR vaccine, protection against measles lasts a lifetime for most people. You do not need booster shots as an adult unless you're in a high-risk situation, such as working in healthcare or traveling to a country where measles is common.

If you're unsure whether you've been vaccinated or want to know if you're protected, your doctor can order a blood test to check your immunity. This test, called a titer, measures whether your body has antibodies against measles. If the test shows you're not immune, you can receive the vaccine even as an adult.

Measles vaccine and pregnancy

Pregnant people should not receive the MMR vaccine because it contains a live virus. However, the vaccine is safe to give after pregnancy, including while breastfeeding. If you're planning to become pregnant and are unsure of your vaccination status, talk to your doctor about getting vaccinated before conception.

If you were vaccinated during pregnancy by accident, this is not considered an emergency. The risk of harm to the pregnancy from the vaccine is theoretical and has not been documented in practice. Contact your doctor to discuss your specific situation, but accidental vaccination during pregnancy is not a reason to end a pregnancy.

The measles vaccine and disease prevention

The measles vaccine has prevented millions of deaths worldwide since it was introduced in 1963. In countries with high vaccination rates, measles is rare. When outbreaks do occur, they almost always happen in communities with lower vaccination rates, and vaccinated people in those communities are protected.

Vaccination also protects people who cannot receive the vaccine themselves—infants too young for their first dose, people with certain immune conditions, and people with severe allergies. When enough people in a community are vaccinated, the virus has fewer people to infect and eventually dies out. This is called herd immunity.

Frequently Asked Questions

Can the measles vaccine give you measles?

No. The vaccine contains a weakened virus that cannot cause measles disease in healthy people. You may develop a mild rash or low fever as your immune system responds, but this is not measles and is not contagious.

What if I was vaccinated but still got measles?

This is rare but possible. About 3 out of 100 people vaccinated with two doses can still get measles if exposed to the virus. When vaccinated people do get measles, the illness is usually much milder than in unvaccinated people, with fewer complications.

Is the MMR vaccine safe?

Yes. The MMR vaccine has been used for over 60 years and has been given to hundreds of millions of people worldwide. Serious side effects are extremely rare. Your doctor can discuss any specific health concerns you have about the vaccine.

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

If you had measles, you have lifelong immunity and do not need the vaccine. However, if you're unsure whether you actually had measles or just think you did, a blood test can confirm your immunity before deciding whether vaccination is needed.

Can adults get the measles vaccine?

Yes. Adults who were never vaccinated, were vaccinated only once, or whose vaccination status is unknown can receive the MMR vaccine at any age. This is especially important for people who work in healthcare, travel internationally, or live in areas with measles cases.