US at risk of losing measles elimination status amid series of outbreaks that started a year ago

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The United States is on the verge of losing its measles elimination status — a designation it has held for 25 years.

Large, linked outbreaks spreading across multiple states, driven by falling vaccination rates, rising exemptions and confused or hostile vaccine messaging from federal and some state leaders, now threaten to establish sustained transmission chains.

If any outbreak continues for 12 months or more, the country officially loses the elimination status it achieved in 2000, when the virus was proven to no longer be spreading continuously within U.S. borders. As the current resurgence is marked as officially beginning with the West Texas outbreak on Jan. 20, 2025, the U.S. would have to show the virus has not been cirulating continuously through this past Tuesday.

Case counts last year were at their highest since 1991. With last year’s outbreak, whether the U.S. will keep its status is in question.[1]

How the US gained elimination status

In 1994, countries in the Americas (through the Pan American Health Organization) set a goal to interrupt endemic measles transmission in the region by 2000. [2]

The U.S. ramped up its measles vaccination program (two-dose MMR), pushed school-entry requirements and built detailed case surveillance and lab confirmation systems so that by the late 1990s, measles was reduced to imported cases and short-lived clusters. [3]

In March 2000, the Centers for Disease Control and Prevention’s National Immunization Program convened an external expert panel, which reviewed measles epidemiology, vaccine coverage and surveillance quality against preset benchmarks and concluded that the criteria for elimination had been met. [2]

What elimination status means and how it is kept

The PAHO and World Health Organization define measles elimination in a country as interruption of endemic measles virus transmission for at least 12 consecutive months with high-quality surveillance; endemic means continuous transmission for 12 months or more. [4]

Other diseases and countries with elimination status

PAHO verified elimination of endemic measles transmission in the Americas region in 2016 and elimination of rubella and congenital rubella syndrome in 2015, although Brazil and Venezuela temporarily lost measles-free status and later regained it. [5]

The Americas have also eliminated wild poliovirus which was verified in 1992, a separate eradication effort that preceded the measles/rubella push and is often cited as a model for the measles initiative. [5]

As of the mid-2020s, all PAHO member countries other than the ones with temporary setbacks have had measles elimination verified as of 2024. [5]

Why measles is spreading now and how severe it is

Measles requires extremely high immunity — typically above 95% — to prevent sustained spread; even modest drops create pockets where the virus can take off. [5]

Since 2020, multiple states have loosened or failed to strengthen school vaccine requirements, and nonmedical exemptions have climbed; a record approximately 138,000 U.S. kindergartners obtained vaccine exemptions for the 2024-25 school year, signaling growing gaps in herd immunity. [1]

Recent analyses show rising nonmedical exemption rates in counties across the U.S., with some communities showing 8% or higher exemption rates, well above the level that destabilizes measles control. [7]

2025-26 outbreak data and severity

A total of 2,255 measles cases were recorded in 2025 in 45 states, with only 25 cases reported among international visitors. [5]

Last year, 94% of cases were outbreak-associated, and 93% of cases occurred in unvaccinated people. About 11% of patients required hospitalization and at least three measles-associated deaths were documented. About 26% of cases are found in children under 5 years old.[5]

South Carolina’s began in October and has seen rapid expansion, with 248 new cases in the week of Jan. 11 and reached at least 558 cases, demonstrating how sustained transmission in undervaccinated communities can unfold. [7]

Current risk to US elimination status

To retain its measles elimination designation, the U.S. must show that no chain of transmission has persisted for a full year, which requires genetic and epidemiologic linkage analyses of outbreaks in Texas, South Carolina, Utah, Arizona and other affected areas. [8]

PAHO has indicated that if endemic transmission (continuous spread of 12 months or longer) is documented, the U.S. would lose its measles-free status. The Americas as a region already lost its status in November due to an outbreak in Canada. [9]

Political and leadership responsibility

Multiple factors drive the resurgence, including longstanding antivaccine movements, pandemic-era erosion of trust in public health, state-level policy changes that weaken school mandates, and the spread of misinformation on social media. [10]

Under Health Secretary Robert F. Kennedy Jr., a prominent vaccine critic, federal agencies have sent mixed signals about vaccine safety and mandates, which public health experts say has undermined confidence in routine childhood vaccines. [11]

Investigations report that the Trump administration impeded the CDC’s ability to assist West Texas during “the first critical weeks” of its outbreak and slowed release of emergency funds, potentially worsening local spread before eventually increasing support and vaccine deployment. [1]

President Donald Trump’s decision to appoint Kennedy as HHS secretary in 2025 placed a longtime vaccine skeptic in charge of the CDC, Food and Drug Administration, and other key agencies; senators, including Mitch McConnell, R-Ky., publicly criticized this choice because of concerns about efforts to roll back vaccine policies. [12]

Kennedy’s early moves to “remake” the Department of Health and Human Services, and his public critiques of existing vaccine programs, have coincided with confused federal guidance on immunization and emboldening of antivaccine activists who oppose school mandates and routine shots. [13]

Separate analysis notes that the Trump administration has recently downgraded or removed several Medicaid immunization reporting measures, making it easier for states to underreport or ignore vaccination performance, which could further weaken oversight of childhood coverage. [19]

What would be the significance if US loses elimination status

Losing elimination status would not mean measles is as widespread as in the prevaccine era, but it would signal that the U.S. has allowed continuous endemic transmission of a vaccine-preventable disease after 25 years of success. CDC Principal Deputy Director Dr. Ralph Abraham said losing the designation would “not really” be significant, as communities choosing to be unvaccinated can be chalked up to “personal freedom.”[20]

PAHO leadership has called similar losses of status in the Americas a “setback” that is reversible but serious. [9]

How the US can regain measles elimination status

If the U.S. loses measles elimination status, it could regain that designation by interrupting all chains of endemic transmission for at least 12 consecutive months,PAHO has seen this process succeed before — Brazil and Venezuela regained status after setbacks through coordinated regional action rigorously. [9]

Key steps to take could include:

• Boost vaccination coverage: Achieve and sustain 95% or higher coverage with two doses of MMR vaccine among children (especially in pockets with high exemptions), using school mandates, catch-up campaigns like “Big Catch-Up” and electronic registries to track and close immunity gaps. [6]
• Strengthen surveillance and labs: Ensure rapid case reporting (within 24 hours to CDC), high-quality lab confirmation (at least 80% of suspects tested, including PCR for early cases) and genomic sequencing to link cases and distinguish importations from endemic spread. [20]

Expand electronic immunization and surveillance systems nationwide, with funding for labs to maintain sustainable capacity for measles detection. [21]

Improve outbreak response

Isolate suspects immediately, provide postexposure prophylaxis (MMR within 72 hours or immunoglobulin within six days) to contacts and conduct ring vaccination around cases to halt spread. [22]

Coordinate federal-state-local efforts for contact tracing, community vaccination drives and documentation of outbreak closure per PAHO guidelines. [23]

Addressing vaccine skepticism

Vaccine skepticism, a major driver of the U.S. measles resurgence, can be addressed through transparent communication, community trust-building and policy incentives rather than confrontation, drawing from public health strategies proven effective in past recoveries like Brazil’s measles status regain. [14]

Transparent messaging:

Clear, evidence-based federal and local communication counters misinformation by emphasizing measles vaccine safety data (over 97% effective after two doses), real-world outbreak risks (32% hospitalization rate in recent cases) and differences from COVID-era mRNA vaccines, which eroded trust via overpromising on transmission prevention. Avoid fear tactics; use personal stories from hospitalized children and simple visuals showing herd immunity thresholds (95% coverage needed). [15]

Policy and access fixes:

Eliminate nonmedical school exemptions. [16]

Fund free, no-appointment MMR shots at pharmacies and schools to remove barriers for working families. [14]

 

Sources

[1] https://kffhealthnews.org/news/article/measles-free-status-us-cdc-ralph-abraham-paho-who-outbreaks-vaccines/

[2] https://www.kff.org/other-health/measles-elimination-status-what-it-is-and-how-the-u-s-could-lose-it/

[3]https://academic.oup.com/jid/article/202/10/1520/823997

[4] https://www.cdc.gov/global-measles-vaccination/what/index.html

[5] https://pmc.ncbi.nlm.nih.gov/articles/PMC11648175/

[6] https://www.who.int/publications/i/item/9789240075511

[7] https://www.npr.org/2026/01/16/nx-s1-5677299/measles-outbreak-vaccines-kids-health

[8] https://abcnews.go.com/Health/1-year-measles-cases-found-texas-us-surge/story?id=129344223

[9] https://www.paho.org/en/news/10-11-2025-paho-calls-regional-action-americas-lose-measles-elimination-status

[10] https://pmc.ncbi.nlm.nih.gov/articles/PMC10946219/#:~:text=The%20ongoing%20outbreaks%20of%20measles,this%20vaccine%2Dpreventable%20viral%20infection.

[11] https://www.latimes.com/science/story/2026-01-22/measles-resurgence-puts-u-s-at-risk-of-losing-its-elimination-status

[12] https://www.npr.org/sections/shots-health-news/2025/02/13/nx-s1-5294591/rfk-jr-trump-health-human-services-hhs-vaccines.

13] https://www.americanprogress.org/article/rfk-jr-is-systematically-undermining-vaccine-science-and-endangering-health/#:~:text=Kennedy’s%20broken%20promises%20threaten%20vaccine,working%20to%20prevent%20future%20pandemics.

[14] https://www.bioprocessintl.com/therapeutic-class/vaccine-hesitancy-and-the-return-of-measles-to-the-us

[15] https://www.healthline.com/health-news/us-measles-outbreak-2026/

[16]https://www.cnn.com/2026/01/14/health/vaccine-exemptions-county-risk-measles-vis

[17] https://www.unmc.edu/healthsecurity/transmission/2026/01/21/vaccine-myths-that-wont-die-and-how-to-counter-them-part-1/

[18] https://www.chop.edu/vaccine-update-healthcare-professionals/newsletter/measles-fast-facts-healthcare-providers

[19] https://www.kff.org/medicaid/trump-administration-drops-medicaid-vaccine-reporting-requirements/

[20] https://pmc.ncbi.nlm.nih.gov/articles/PMC7492366/

[21] https://www.cdc.gov/surv-manual/php/table-of-contents/chapter-7-measles.html#:~:text=Laboratory%20confirmation%20of%20measles%20infection,for%20confirmation%20of%20measles%20infection.

[22] https://www.cdc.gov/field-epi-manual/php/chapters/coordinating-agencies.html#:~:text=Roles%20of%20selected%20government%20agencies,FDA

[23] https://www.cdc.gov/measles/hcp/vaccine-considerations/index.html