Already, the U.S. has more measles cases this year than in all of 2024, the U.S. Centers for Disease Control and Prevention has said. Other states with outbreaks — defined as three or more cases — include New Mexico, Kansas, Ohio and Oklahoma. Since February, two unvaccinated people have died from measles-related causes.

The measles outbreak that began in northwest Texas has now surpassed a combined 500 cases in Texas, New Mexico and Oklahoma.

The number of measles cases from the outbreak in West Texas is nearing 500 as close to 60 infections were reported in just three days. Here are key things to know about measles and the outbreaks in the U.