A measles outbreak spanning the Arizona and Utah border has grown to 123 infections. The communities involved in the outbreaks are known to be susceptible to measles due to low vaccination rates, far below the 95% vaccination rate needed for herd immunity. In Mohave County, Arizona, 78.4 percent of kids have received measles vaccination. In Utah, Iron County and Washington County, pediatric vaccination rates of are 82.4 percent and 79.2 percent, respectively. In 2025, the US has confirmed 1,618 measles infections in 42 states.
