The US is on the verge of losing its measles elimination status. Here’s why that matters

U.S. Measles-Free Status Under Review as Cases Surge Nationwide

International health authorities will meet in April to determine if the United States has lost its measles-free designation, following a year-long outbreak that began in West Texas. The reevaluation comes as experts worry the vaccine-preventable virus has regained a foothold in the country, potentially following Canada’s recent loss of its elimination status.

While largely symbolic, the decision hinges on whether a single chain of measles has spread uninterrupted within U.S. borders for at least 12 months. Public health scientists are investigating possible links between the recently ended Texas outbreak and ongoing ones in Utah, Arizona, and South Carolina.

“It is really a question of semantics,” said Dr. Jonathan Temte, a Wisconsin family physician who helped certify the U.S. as measles-free in 2000. “The bottom line is the conditions are sufficient to allow this many cases to occur. And that gets back to de-emphasizing a safe and effective vaccine.”

The Centers for Disease Control and Prevention confirmed 2,242 measles cases across 44 states last year – the most since 1991 – with nearly 50 separate outbreaks. This resurgence follows years of declining childhood vaccination rates due to parental waivers, healthcare access issues, and widespread misinformation.

The situation has been further complicated by Trump administration health officials, including Health Secretary Robert F. Kennedy Jr., who have publicly questioned vaccine safety while reducing funding for local vaccination initiatives. A Department of Health and Human Services spokesperson countered Thursday that Kennedy has emphasized vaccines as the best way to prevent measles.

Jennifer Nuzzo, director of Brown University’s Pandemic Center, emphasized the need for clear communication: “The most important thing that we can do is to make sure the people who aren’t vaccinated get vaccinated. We have not issued a clear enough message about that.”

During a Tuesday briefing, department officials stated they don’t yet have evidence of a year-long continuous chain of transmission. CDC Principal Deputy Director Dr. Ralph Abraham described a potential loss of elimination status as the “cost of doing business” globally, noting, “We have these communities that choose to be unvaccinated. That’s their personal freedom.”

Measles is extraordinarily contagious, infecting 9 out of 10 unvaccinated people exposed to it. Community protection requires a 95% vaccination rate, but the current national average stands at just 92.5%, with many areas falling significantly lower.

The Texas outbreak began in January 2025 when a patient developed the characteristic rash. The virus spread rapidly, particularly in rural Gaines County, resulting in 762 confirmed cases and two child fatalities. Health officials believe many more cases went undiagnosed – in March 2025 alone, 182 potential measles cases among children in Gaines County remained unconfirmed.

Such data gaps make outbreak tracking challenging. Communities experiencing virus spread often face healthcare access barriers and government distrust. Contact tracing is resource-intensive, with research showing a single measles case can cost public health departments tens of thousands of dollars.

“The U.S. has changed its investment in public health, so we’re less able to do the case tracking that we used to do,” said behavioral scientist Noel Brewer, who chairs the U.S. committee finalizing data for international health officials.

Genetic sequencing has confirmed the same measles strain in Texas, New Mexico, Utah, Arizona, South Carolina, Canada, Mexico, and several other North American countries, according to Sebastian Oliel, spokesperson for the Pan American Health Organization (PAHO), which will make the final determination on U.S. status.

However, genetic similarity doesn’t definitively prove connection between outbreaks, as the measles virus doesn’t mutate as rapidly as other pathogens. “Within an outbreak, everybody is going to look the same,” explained Justin Lessler, a University of North Carolina disease researcher.

Dr. Andrew Pavia, a Utah physician and CDC consultant, believes the outcome will likely be unfavorable: “My best guess is we will lose elimination status. The case for this not being continuous transmission is tenuous.”

PAHO will simultaneously review Mexico’s measles-free status, where an outbreak with roots in Texas has sickened 6,000 people and killed 21 in Chihuahua state. The outbreak began when an 8-year-old boy fell ill after visiting family in Seminole, Texas.

Throughout 2025, measles found ample opportunity to spread in the U.S., infiltrating schools, daycares, churches, hospital waiting rooms, and a detention center. New Mexico reported 100 cases and one adult death, while Kansas officials spent seven months controlling an outbreak that affected nearly 90 people across 10 counties.

Currently, over 800 people have been infected in Utah, Arizona, and South Carolina since late summer, with no resolution in sight.

“2025 was the year of measles,” Brewer remarked. “Will 2026 be the year of rising or falling measles cases? Does it get worse or does it get better? No one knows the answer.”