Texas has more than 600 known cases of measles on Tuesday as the outbreak in the western part of the state approaches the three-month mark.

The U.S. was up to 800 cases of measles nationwide on Friday. Two unvaccinated elementary school-aged children died from measles-related illnesses in the epicenter in West Texas, and an adult in New Mexico who was not vaccinated died of a measles-related illness.

Other states with active outbreaks—defined as three or more cases—include Indiana, Kansas, Michigan, Montana, Oklahoma, Ohio, Pennsylvania, and New Mexico. The U.S. has more than double the number of measles cases it saw in all of 2024.

North America has two other outbreaks. One in Ontario, Canada, has sickened 925 from mid-October through April 16. And as of Tuesday, the Mexican state of Chihuahua state has 514 measles cases, according to data from the state health ministry. The World Health Organization has said cases in Mexico are linked to the Texas outbreak.

Measles is caused by a highly contagious virus that’s airborne and spreads easily when an infected person breathes, sneezes, or coughs. It is preventable through vaccines, and has been considered eliminated from the U.S. since 2000.

As the virus takes hold in other U.S. communities with low vaccination rates, health experts fear the virus that the spread could stretch on for a year. Here’s what else you need to know about measles in the U.S.

Texas state health officials said Tuesday there were 27 new cases of measles since Friday, bringing the total to 624 across 26 counties—most of them in West Texas. Two more Texans were hospitalized, for a total of 64 throughout the outbreak, and Bailey County logged its first two cases.

State health officials estimated about 2% of cases—fewer than 10—are actively infectious.

Sixty-two percent of Texas’ cases are in Gaines County, population 22,892, where the virus started spreading in........

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