“Infected people are contagious from 4 days before the rash starts through 4 days afterward. The incubation period for measles, from exposure to fever, is usually about 7-10 days, and from exposure to rash onset is usually about 10-14 days (with a range of 7 to 21 days),” the CDC says.

Two people have died from measles as the U.S. faces outbreaks of the highly contagious virus. Can you get measles if you're vaccinated? Experts explain.