The United States has a total of 607 confirmed measles cases as of Thursday, according to the Centers for Disease Control. Of those 607 cases, 72% are people who are 19-years old or younger with 97% being unvaccinated or with an unknown vaccination status.

Kelsey Striegel, family nurse practitioner at Washington County Hospital and Clinics, states measles is highly contagious and she shares how best to prevent contracting the illness, “So of course, washing your hands and covering sneezes is important, but really, truly the most important thing to do to prevent measles is to vaccinate. One dose of the MMR vaccine is considered to be 93% effective at preventing infection and two doses is 97% effective.”

According to the CDC, measles spreads through the air when an infected person coughs or sneezes and others can contract measles by being in a room where a person with it has been – even up to two hours after that person has left the room. Symptoms may appear days after exposure and can include high fever, cough, runny nose, red and watery eyes, and a rash.

Last year, the U.S. had a total of 285 cases of measles for the entire calendar year.