The number of measles cases in the US has reached a 35-year high, with 2,318 cases reported as of Thursday, according to the US Centers for Disease Control and Prevention. This surpasses the record-breaking tally for all of 2025, with five more months of 2026 still to come.

Outbreaks in Multiple States

Major outbreaks in South Carolina, Utah, and Arizona have sickened hundreds, while smaller clusters of cases have sparked in other states. The US had 2,289 cases in 2025, the worst year for measles in more than three decades.

Experts say the spread might be greater than what’s known because the virus is one of the most contagious known to medicine and vaccination rates nationwide have declined. National vaccination rates for measles, mumps, and rubella dropped to 92.5% among kindergartners in the 2024-25 school year, from 95.2% in 2019-20.

In Utah, where public health officials have fought measles for more than a year, the virus has sickened more than 700 people during that time, according to the state health department. Experts relying on mathematical modeling and genetic analyses indicate that a large outbreak on the Utah-Arizona border could be around three to four times bigger than what’s currently known.

Dr. Mark Roberts, retired director of the Public Health Dynamics Lab at the University of Pittsburgh School of Public Health, worries most for the people he calls ‘innocent bystanders.’ Research and measles modeling by his team shows those who cannot get vaccinated — young babies, people with weak immune systems, and those who rarely don’t get robust immunity from the vaccine — bear the brunt of outbreaks early on.

Not vaccinating one’s child is like saying, ‘I don’t want my car to have brakes,’ Roberts said. ‘Because it’s other people that you can hit. It’s not just you in your car. It’s other people.’

Original reporting: Dallas TX News (HLL/CB) — read the source article.