A hospital in Texas on Wednesday confirmed the death of an unvaccinated child who was infected with measles—the first fatality in a two-state measles outbreak that began in January, according to the Associated Press.

A child who wasn’t vaccinated died in a measles outbreak in rural West Texas, officials there said Wednesday, the first U.S. death from the highly contagious respiratory disease since 2015.

If the current outbreaks in the US have you thinking about scheduling an appointment, the message is: the sooner the better.