What Is Measles?

The measles virus lives in the mucus of your nose and throat. It’s spread through the air and by coming into direct contact with someone who has it. The virus can stay active on surfaces and in the air for up to 2 hours.

It’s very contagious. If you haven’t been vaccinated and are in a room with someone who has measles, you have a 90% chance of getting it.

Part of what makes measles so dangerous is that you can be contagious 4 days before you get the telltale rash. So you could easily spread the virus without knowing you have it. You’ll continue to be contagious 4 days after the rash goes away.

Measles Symptoms

A high fever is normally the first sign of measles. It usually starts 10 to 12 days after you were exposed to the virus. The fever will last 4 to 7 days. During that time, you might develop the following symptoms:

  • Runny nose
  • Red eyes
  • Sore throat
  • Tiny white bumps in your mouth (doctors call these Koplik spots)
  • Rash. It usually starts at the hairline and spreads to the neck, torso, limbs, feet, and hands.

If you get measles, you’ll be sick for a couple of weeks. Fortunately, it’s preventable.


The Measles Vaccine

Immunizations are by far the best way to prevent the spread of measles. Thanks to the measles-mumps-rubella (MMR) vaccine, the virus has been mostly wiped out in the United States. That doesn't mean no one gets measles anymore; it’s just not constantly around. If you live in the U.S. and do get it, it's usually because someone brought it in from another country.

The MMR vaccine is 97% effective after two doses. Doctors recommend that children get the first dose when they're between 12 and 15 months old, and the second between 4 and 6 years old.

The vaccine is safe for most people. Pregnant women, people with weakened immune systems (from diseases like leukemia and tuberculosis), and those with certain allergies can’t get the vaccine. As a result, the odds are higher that they’ll get the virus if they are exposed to it.



If you do get the measles virus, medicine won’t cure it (drugs don’t kill viruses). The best way to speed up the recovery process and prevent complications is to drink plenty of fluids and get lots of rest.

In the U.S., about 1 in 4 people who get measles end up in the hospital. Children under age 5 and adults over age 20 tend to have the worst problems. These may include:

WebMD Medical Reference Reviewed by Dan Brennan, MD on March 23, 2019



World Health Organization: “Measles Fact Sheet.”

CDC: “Measles,” “Top 4 Things Parents Need to Know About Measles.”

KidsHealth: “Infections: Measles.”

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