Outbreaks of measles have the US on the brink of losing its elimination status
- Charles Reams 1
- Jan 1
- 2 min read
The United States reported more than 2,000 measles cases in 2025.
How has the highest annual total impacted the measles elimination status?
A medical elimination status means a specific infectious disease is no longer constantly present in a region, though it can still be reintroduced from elsewhere. It’s achieved through successful public health efforts, such as vaccination, resulting in 12 months of continuous local transmission, as verified by organizations like the World Health Organization (WHO).
Outbreaks — particularly in the upstate region of South Carolina and along the border between Arizona and Utah — continue to add dozens of cases each week, threatening the measles elimination status that the US has held for a quarter-century.
As of December 30, there have been 2,065 confirmed measles cases in the US in 2025, according to data published Wednesday by the US Centers for Disease Control and Prevention.
Measles is one of the most contagious diseases known, but the MMR vaccine offers highly effective protection. One dose is 93% effective against measles infection, and two doses are 97% effective, according to the CDC.
In early October, the South Carolina health department confirmed that there was a measles outbreak in the upstate region. That outbreak has spread to nearly 180 cases over the past four months and continues to grow; at least 20 new cases have been reported since Friday, and nearly 300 people are in quarantine because of exposure to a known case.
“We know that a large number of our cases are those who we’ve placed in quarantine because of known exposures,” Dr. Linda Bell, South Carolina’s state epidemiologist, said Tuesday. Measles continues to spread through household transmission, in schools and at churches, she said.
The World Health Organization has determined that Canada had lost its measles elimination status amid a large ongoing outbreak there.
But possible genetic links between the Texas outbreak and the ongoing South Carolina outbreak put that status at risk for the US.
“The trajectory that we’re looking at now is that we do anticipate more cases well into January,” Bell said.
