Measles outbreaks: Here's who should get a booster shot

As public health officials monitor a rise in U.S. measles cases, some may be wondering if they need a booster vaccine to protect themselves. 

Five states have confirmed measles cases so far in 2025, with a larger outbreak reported in West Texas. It’s the second consecutive year that the U.S. is reporting a rise in cases. 

What is measles? 

The backstory:

Measles is a highly contagious virus that can survive in the air for up to two hours. Up to 9 out of 10 people who are susceptible will get the virus if exposed, according to the U.S. Centers for Disease Control and Prevention. Before the vaccine was introduced in 1963, the U.S. saw some 3 million to 4 million cases per year. Now, it’s usually fewer than 200 in a normal year.

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Where are measles cases being reported? 

Measles cases have been reported in Alaska, Georgia, New York, Rhode Island and Texas, according to the CDC. All of the people infected are unvaccinated. 

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Who needs an MMR vaccine? 

The CDC recommends all children get two doses of the measles, mumps and rubella (MMR) vaccine. The first dose should be given at 12-15 months of age, and the second dose should be administered between 4 and 6 years old. 

Children may also get the MMRV vaccine, which protects against measles, mumps, rubella, and varicella (chickenpox). This vaccine is only licensed for use in children who are 12 months through 12 years of age.

College students who don’t have presumptive evidence of immunity need two doses of MMR vaccine, separated by at least 28 days.

Adults who don’t have presumptive evidence of immunity should get at least one dose of MMR vaccine, but healthcare workers, college students and international travelers should get two doses, at least 28 days apart. 

Do you ever need a measles booster vaccine? 

If you’ve had two doses of MMR vaccine, you don’t need a booster, according to public health officials. The vaccine protection lasts for life.

Adults need at least one dose of measles vaccine, unless they have evidence of immunity. If you are a healthy adult with one documented MMR vaccine, you are fully protected. 

International travelers and healthcare workers need two doses.  

Dig deeper:

According to the CDC, people who have documentation of receiving live measles vaccine in the 1960s do not need to be revaccinated. People who were vaccinated before 1968 with either inactivated (killed) measles vaccine or measles vaccine of unknown type should be revaccinated with at least one dose of MMR vaccine. The killed vaccine was available from 1963-1967 and was found to be ineffective. 

Is it safe to get another MMR vaccine?

If you are unsure of your vaccine history or just want peace of mind, it is safe to get another MMR vaccine.