Federal data shows that the United States reported over 2,000 measles cases in 2025, with clusters in South Carolina and along the Arizona-Utah border highlighting growing gaps in vaccination coverage.
As of December 30, 2025, there were 2,065 confirmed cases, according to the Centers for Disease Control and Prevention (CDC). This marks the highest annual total in decades, the last time the US reported more than 2,000 cases was in 1992, shortly after health authorities recommended two doses of the measles-mumps-rubella (MMR) vaccine instead of one.
Measles is one of the most contagious diseases known, but the MMR vaccine provides highly effective protection: 93% effective with one dose and 97% effective with two doses, the CDC notes.
Despite this, health officials say vaccination rates have been slipping. For the 2024–25 school year, only 92.5% of incoming kindergarteners had received the MMR vaccine, below the 95% coverage threshold public health experts say is necessary to prevent outbreaks.
They warn that increasing vaccination coverage is critical to stopping the spread of measles and protecting communities. They stress that outbreaks like these highlight the ongoing need for public education, accessible vaccines, and vigilance against preventable diseases.
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