One year ago, health officials confirmed that cases of measles were cropping up in a small town in western Texas. By the time 2025 ended, more than 2,200 cases had been confirmed, the highest number reported in the U.S. in 33 years, according to data from the Centers for Disease Control and Prevention. The U.S. also saw its first measles deaths in more than a decade including two among unvaccinated school-aged children in Texas and one among an unvaccinated adult in New Mexico. If it's determined that the U.S. has experienced 12 months of continuous measles transmission, it could lead to a loss of the country's elimination status that was earned in 2000. Measles would once again be considered endemic or constantly circulating.