US Measles Cases Exceed 2,000 as Experts Warn Loss of Elimination Status Is ‘Highly Likely’
The United States is losing its grip on measles. With 2,073 confirmed cases across 40 states and jurisdictions in 2026 alone — already approaching the 2,288 cases that marked 2025 as the worst year since the disease was declared eliminated in 2000 — health experts are warning that the country may be on the verge of losing its elimination status entirely.
A progress report published in The Lancet by researchers at Boston Children’s Hospital assessed seven indicators used by the Pan American Health Organization (PAHO) to certify measles elimination. Their conclusion: the US has definitively missed at least four of them.
“Four of the seven criteria are very clearly not met,” said Maimuna Majumder, PhD, a distinguished scholar at Boston Children’s Hospital and co-author of the Lancet analysis. “I would be very surprised to see it turn out otherwise” at PAHO’s November 2026 recertification meeting.
The data behind the warning
CDC data as of June 11 shows the scale of the resurgence. Of the 2,073 cases reported in 2026, 93% (1,929 cases) are outbreak-associated. More than half — 51% — are in children aged 5 to 19 years, the school-age population where vaccination gaps are most consequential. Children under 5 account for 21% of cases, and adults 20 and older for 28%.
Hospitalizations have reached 128 (6% of cases), with the highest rate in children under 5 (10%) and adults over 20 (9%). No deaths have been reported so far in 2026, compared with three in 2025.
The geographic distribution is broad. South Carolina leads with 670 cases, followed by Utah (490), Texas (182), Florida (141), and Virginia (110). The Utah outbreak is nearing its one-year mark, a signal of sustained community transmission rather than isolated importations.
The seven indicators
PAHO uses a framework of seven indicators to evaluate a country’s measles elimination status. The Boston Children’s team assessed each one:
- Incidence rate: The US should have fewer than 1 case per 10 million population. The actual rate is approximately 93 per 10 million. Missed.
- Outbreak frequency: No more than 4 outbreaks per year, each involving roughly 6 cases. In 2025 there were 48; 2026 has already recorded 30. Missed.
- Effective reproductive number (R) below 1: The virus should not be sustaining itself domestically. R has been above 1 for more than 75% of the time since the resurgence began. Missed.
- Genotyping diversity: Eliminated measles shows multiple viral lineages from separate importations. The US now sees a single dominant lineage, indicating sustained domestic transmission. Missed.
The remaining three indicators — related to laboratory surveillance capacity, outbreak response timeliness, and reporting completeness — are also at risk. PAHO’s expert panel will review all seven at the November meeting.
A critical finding from the Lancet analysis: only 6-7% of current US measles cases can be traced to international sources. In an eliminated setting, nearly all cases should be import-related. The fact that more than 93% of cases are domestically acquired marks a fundamental shift in the epidemiology.
Vaccination coverage at a record low
Underpinning the resurgence is a steady erosion of MMR vaccination coverage. CDC’s SchoolVaxView data for the 2024-2025 school year shows that only 92.5% of kindergartners nationwide have received two doses of the MMR vaccine — below the 95% threshold required for herd immunity.
Exemption rates have reached an all-time high of 3.6%, with non-medical exemptions at 3.4%. Seventeen states report exemption rates above 5%. Idaho has the lowest MMR coverage in the nation at 78.5%, followed by Alaska (81.2%), Wisconsin (84.8%), Georgia (86.8%), and Arizona and Utah (both 88.6%).
California, which passed strict vaccination laws (SB-277) after the 2014-2015 Disneyland outbreak, maintains one of the highest coverage rates at 96.1%.
“The levers that you would typically use to rescue elimination status are no longer viable,” Majumder told Live Science, describing the current federal environment as “radically different” from the post-Disneyland era.
The political context
The resurgence is unfolding under a second Trump administration with Robert F. Kennedy Jr. confirmed as Secretary of Health and Human Services since early 2025. Both experts interviewed for the Lancet analysis and the Live Science article described the federal communication strategy as one that creates “skepticism” about vaccines.
Anne Bischops, a pediatrician and postdoctoral research fellow at Boston Children’s Hospital and co-author of the Lancet report, said she sees the consequences directly in the emergency room: “It only takes one short online comment to spread doubts.” She and Majumder both noted that vaccine fatigue since the COVID-19 pandemic has compounded the problem, making it harder to mobilize the kind of public health response that successfully contained past outbreaks.
What losing elimination status means
If PAHO revokes the US elimination status in November, it would be a formal acknowledgment that measles is once again endemic in the country — a disease that was declared eliminated in 2000 after decades of vaccination campaigns.
The practical consequences include reduced credibility for US public health agencies in global health forums, potential travel advisories from other countries, and a psychological setback for vaccination efforts. But the most direct consequence is measured in cases: before the vaccine, the US recorded 481,530 cases in 1962 and 763,094 in 1958. Measles hospitalizes roughly 1 in 5 unvaccinated people who contract it and kills 1-3 per 1,000, primarily from pneumonia and encephalitis.
Both experts interviewed agreed on the likely outcome. “It’s highly likely that we will, sadly, lose status,” Bischops said.
Sources
Bischops A, Majumder M, et al. Will the USA lose its measles elimination status? The Lancet. April 30, 2026. DOI: PIIS0140-6736(26)00466-6
CDC. Measles Cases and Outbreaks. Data as of June 11, 2026. https://www.cdc.gov/measles/data-research/index.html
Wang et al. Characteristics of Patients Hospitalized with Measles During an Outbreak — West Texas, January-March 2025. MMWR. 2026;75(20):252-257. May 28, 2026.