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Measles is caused by a virus and spreads very easily when an infected person breathes, coughs, or sneezes. It spreads so easily that someone who is not protected (either by being immunized or having had measles in the past) can get it if they walk into a room where someone with the disease has been in the past couple of hours.

Learn more about measles vaccine safety and monitoring and information for pregnant people and new parents

Measles is very contagious and can cause serious illness. About one out of 10 children with measles also gets an ear infection, and up to one out of 20 gets pneumonia. One or two out of 1,000 die from measles complications. Measles can also cause pregnant woman to miscarry or give birth prematurely. Serious health problems from measles are more common among children younger than five and adults older than 20.

Measles spreads so easily that anyone who is exposed to it and is not immune (for example, someone who has not been vaccinated) will probably get the disease.

Measles causes fever, runny nose, cough, conjunctivitis (red, watery eyes) and a rash all over the body. People can spread measles before they show symptoms. Symptoms usually last 7-10 days.

Getting the measles, mumps, rubella (MMR) vaccine is the best protection against measles. The MMR vaccine is very safe and effective. Two doses of MMR vaccine are about 97% effective at preventing measles; one dose is about 93% effective. When more than 95 percent of people are vaccinated against measles, the disease slows down and doesn’t spread. This is called community (or herd) immunity.

If you’re unsure whether you’re immune to measles, you should first try to find your vaccination records or documentation of measles immunity. If you do not have written documentation of measles immunity, you should get vaccinated with measles-mumps-rubella (MMR) vaccine. Another option is to have a doctor test your blood to determine whether you’re immune. But this option is likely to cost more and will take two doctor’s visits. There is no harm in getting another dose of MMR vaccine if you may already be immune to measles (or mumps or rubella).

The Centers for Disease Control and Prevention offers photos that show what measles looks like.

There is no cure for measles. Over-the-counter medications such as Tylenol can help relieve the fever that accompanies measles, and other symptoms typically disappear within two to three weeks. Medical care can help relieve symptoms and address complications such as bacterial infections. Some measles cases require hospitalization.

Vitamin A cannot prevent or cure measles, but is used to prevent severe complications, including death in children with measles. Severe measles cases among children, such as those who are hospitalized, should be treated with vitamin A.

Before the measles vaccine was introduced, measles caused about 400 deaths in the U.S. each year. Most people in the U.S. are now vaccinated against measles or are immune from having measles as a child, but outbreaks do happen. Most commonly, measles is brought into the U.S. by someone who has traveled outside the country. When unvaccinated people are exposed, measles spreads very quickly.

Anyone who hasn’t been immunized or had measles in the past is at risk. Babies younger than 12 months are at risk because they are too young to have been vaccinated. Others at highest risk include children under 5 years, adults over 20 years, pregnant women, and people with weakened immune systems from drugs or underlying disease.

Call your doctor, nurse, or clinic right away. Before you go to the doctor’s office, call to tell them that you or your family member might have measles. This will allow them to take steps to avoid exposing other people. Stay away from other people until at least four days after the rash starts or a test proves it’s not measles.