A second child has died in Texas after contracting measles, The New York Times first reported Sunday—the second confirmed death from the disease in a decade—as more than 600 measles cases have now been confirmed in 20 states, with much of the outbreak centered in northwest Texas.

The US has more measles cases this year than in all of 2024, the CDC said last week. Here’s what else you need to know about the outbreaks.

More than two months in, the West Texas outbreak is believed to have spread to New Mexico, Oklahoma and Kansas, sickening nearly 570 people. The World Health Organization also reported cases related to Texas in Mexico.