What are the measles? What you need to know

Measles is a highly contagious disease that affects primarily children and is accompanied by a skin rash. Ninety percent of people exposed to the measles virus will get infected if they have not been vaccinated. Measles is transmitted by airborne droplets produced during coughing or sneezing, or via direct contact with secretions from the nose, mouth and throat of infected people.

What about the vaccine?

There’s been a measles vaccine — often incorporated with mumps and rubella vaccines, thus called MMR — since the 1960s. Before mass vaccination began in the 1980s, measles killed nearly 2.6 million people a year, according to the World Health Organization. Some vaccine skeptics claim the MMR vaccine causes autism, although many studies have shown that’s not true.

What are measles symptoms?

The serious yet preventable virus causes a high fever, dry cough, runny nose, watery eyes and a signature skin rash of tiny red spots. People can spread the illness up to four days before the rash appears.

While most kids recover after a rash, fever and perhaps a cough, it can lead to serious complications from pneumonia to encephalitis, a brain inflammation that can cause permanent disabilities and sometimes can kill.

Do I need a vaccine booster?

Some infectious disease experts believe a fraction of adults who were vaccinated for measles decades ago as children may now be susceptible to the virus — perhaps up to one in 10 of those who were immunized.

But if you had two doses of measles vaccine as a child — as outlined by the U.S. vaccination schedule — the Centers for Disease Control and Prevention considers you to be protected for life.

What’s the status of measles today?

In 2016, the World Health Organization declared measles has been eliminated in all of the Americas. Elimination means there are no more homegrown cases, but the infection can still be imported from elsewhere to cause outbreaks.

Still, measles outbreaks in the U.S. have continued, some linked to clusters of families that have deliberately delayed or refused to vaccinate children, according to the CDC.

Measles is still common in other parts of the world, including many countries in Europe, Asia, the Pacific, and Africa, the CDC notes.