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Measles is a serious disease that causes rash and fever. Measles can also cause serious problems, including pneumonia, ear infections, and permanent brain damage. About 1 in 4 people who get measles in the U.S. will be hospitalized. In rare cases, it can be deadly. 

Measles is very contagious. The measles virus spreads through the air when a person with measles breathes out, coughs or sneezes. The virus can survive in the air for up to 2 hours after an infected person leaves an area. Someone with measles is contagious 4 days before they have a rash through 4 days after the rash appears.

What counts as evidence of immunity?

  • Birthday before 1957

    People born before the introduction of measles vaccine probably had measles virus.


  • Documented vaccinations

    Record of a measles vaccination:

    • Children ages 1-3 = 1 dose
    • Students ages 4+ = 2 doses
    • Most adults = 1 dose*

    *Healthcare providers, international travelers, and students need two doses of MMR.
    *Measles doses administered between 1963 and 1967 are considered invalid and must be repeated.


  • Lab test results

    A lab test that shows immunity through vaccination or through previous measles infection and a full recovery.

How you can protect against measles

Measles vaccination is your best protection. When you get 2 doses of the measles-mumps-rubella (MMR) vaccine, it’s 97% effective at preventing measles. Numerous studies of MMR vaccine have concluded that the MMR vaccine is safe. Measles vaccine is recommended for everyone 1 year and older.

Declines in measles vaccination rates have increased the risk of measles outbreaks in Washington, the U.S., and around the world. Local cases of measles are often linked to unvaccinated travelers who returned from an area that has measles.


More information on vaccination

Resources for child care facilities and schools

Resources for health care professionals