South Carolina is the epicenter of what state officials call an “accelerating” measles outbreak. Hundreds of people are in quarantine, and the outbreak has sickened at least 111 individuals, most of whom—105—were not vaccinated against the disease. The rash of cases is merely the latest in a string of measles outbreaks across the U.S. this year. Each of these outbreaks has brought the country ever closer to losing its measles-free status after more than 25 years.
As of December 10, the U.S. Centers for Disease Control and Prevention reported 1,912 measles cases, most of which were linked to 47 outbreaks of the disease, this year. For comparison, 2024 saw just 16 outbreaks and 285 cases. At least two children have died of measles in the current outbreaks.
A growing decline in vaccination rates in communities across the country is driving these grim trends. Measles vaccines are generally given as part of the combined measles, mumps and rubella (MMR) shot, two doses of which are 97 percent effective against the disease. The U.S. effectively eliminated measles in 2000 because enough people got the vaccine to suffocate the virus’s spread through the population.
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As part of that effort, the MMR vaccine is required for children to attend public school throughout the country, but many states offer parents the choice to exempt their child for religious or personal reasons. In a media briefing yesterday, South Carolina’s state epidemiologist Linda Bell said that vaccination levels there were simply “lower than hoped for.”
The state has seen vaccination rates of its schools’ students decline from almost 96 percent in 2020 to 93.5 percent in 2025—for context, robust herd immunity from measles requires about 95 percent of the population to be vaccinated, according to the World Health Organization.
Both Secretary of Health and Human Services Robert F. Kennedy, Jr., and President Donald Trump have criticized the shot, suggesting it should be broken up into separate jabs and linking it, without evidence, to autism. Numerous studies have debunked this link.
Editor’s Note (12/11/25): This article was edited after posting to correct the number of people who have been sickened in the current measles outbreak in South Carolina, the description of cases this year that have been linked to 47 outbreaks and the date of the media briefing with Linda Bell.