Lead: The Centers for Disease Control and Prevention reported that the United States has recorded 2,012 measles cases as of Dec. 23, 2025 — the first time annual case counts have exceeded 2,000 since 1992. Cases span more than 40 states and include 24 infections in international visitors. The surge has produced 50 separate outbreaks this year and prompted renewed public-health warnings about vaccination gaps. Health officials say hospitalization has affected 11% of patients, with more than half of those hospitalized under age 19.
Key takeaways
- 2,012 confirmed measles cases in the U.S. were reported to the CDC as of Dec. 23, 2025, surpassing the last comparable total of 2,126 in 1992.
- 24 of the 2,012 cases were identified in international visitors to the U.S.
- Fifty outbreaks were reported nationwide in 2025, compared with 16 outbreaks recorded in 2024.
- About 93% of confirmed cases are among people unvaccinated or with unknown vaccination status; 3% had one MMR dose and 4% had two doses.
- Eleven percent of cases resulted in hospitalization; more than half of hospitalized patients are younger than 19 years old.
- Confirmed cases appear in over 40 states, including large and small jurisdictions from California to Wyoming.
- Kindergarten MMR coverage has slipped to 92.5% in the 2024–2025 school year, down from 95.2% in 2019–2020.
Background
Measles is a highly contagious viral infection preventable with the measles-mumps-rubella (MMR) vaccine. The U.S. achieved near-elimination of endemic measles after widespread vaccination in the late 20th century, but international importations and local pockets of low vaccine uptake have repeatedly sparked outbreaks. Historically, the last year with more than 2,000 cases was 1992, when 2,126 infections were confirmed nationwide.
In recent years, vaccination rates among young children have declined modestly, a trend public-health authorities link to pandemic-era disruptions, access challenges, and vaccine hesitancy in some communities. Measles requires very high population immunity to prevent sustained spread: estimates of the herd-immunity threshold typically exceed 90–95%. When coverage falls below that level in any community, an imported case can seed rapid transmission.
Main event
The CDC’s Dec. 23 tally lists 2,012 cases reported across the U.S., with confirmed infections in Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin and Wyoming. Twenty-four cases have been identified in international visitors.
Public-health investigators documented 50 discrete outbreaks in 2025, more than triple the number reported in 2024. Several outbreaks have been concentrated around schools and community events, forcing quarantines of exposed students and temporary closures in affected districts. The largest single cluster reported to date is in South Carolina, where state officials confirmed 179 cases as of Dec. 30, with 176 of those centered near Spartanburg County on the North Carolina border.
Vaccination-status data collected by the CDC show that roughly 93% of cases occurred in people who were unvaccinated or whose vaccination records were incomplete or unknown. Breakthrough infections occurred but were uncommon: 3% of cases involved individuals with one documented MMR dose and 4% occurred in people who had received the recommended two doses. The CDC continues to recommend two MMR doses: first at 12–15 months and a second between 4–6 years.
Analysis & implications
The near-2,000-case mark signals a sustained shift from the lower annual totals of recent years and illustrates how importations plus local immunity gaps can reignite transmission. Even though measles is vaccine-preventable, the virus’s basic reproduction number (R0) is among the highest of common pathogens, so small declines in coverage can have outsized effects. The clustering of cases in schools and specific communities raises concern for ongoing spread in settings where vaccination levels are below recommended thresholds.
Clinically, most measles cases are self-limited but complications can include pneumonia, encephalitis and death — risks greatest among young children and immunocompromised people. The reported 11% hospitalization rate this year underscores illness severity in a meaningful minority of patients and will add pressure on pediatric and regional hospital services in affected areas. Public-health resources — contact tracing, testing, and quarantine enforcement — have been stretched in several jurisdictions responding to multiple simultaneous outbreaks.
Policy implications are likely to include intensified vaccination campaigns, school-entry checks, and targeted outreach in under-vaccinated communities. Federal and state authorities may increase funding for outbreak response, while health departments will emphasize routine childhood immunizations and easy access to vaccine clinics. International travel screening and traveler vaccination reminders could also be amplified to reduce importation risk.
Comparison & data
| Metric | 1992 | 2025 (as of Dec. 23) |
|---|---|---|
| Total confirmed cases | 2,126 | 2,012 |
| Reported outbreaks (year) | Data not summarized here | 50 |
| Kindergarten MMR coverage | 95.2% (2019–2020) | 92.5% (2024–2025) |
The table highlights that total cases in 2025 are approaching the magnitude last seen in 1992, while kindergarten MMR coverage has declined from pre-pandemic levels. The combination of lower routine coverage and increased outbreaks this year suggests that local susceptibility pockets are the main driver of transmission rather than a uniform national shift.
Reactions & quotes
“Vaccination remains the most effective protection against measles for individuals and communities,”
Centers for Disease Control and Prevention (official guidance)
The CDC reiterated routine two-dose MMR recommendations and urged clinicians to check vaccine records and offer catch-up doses. Officials emphasized rapid identification and isolation of cases to limit spread.
“We are working with local partners to contain clusters and protect children; school-based exposures have driven much of the recent transmission,”
South Carolina Department of Health (official statement)
South Carolina officials described quarantine measures for exposed students and outreach to increase vaccination within Spartanburg County and neighboring areas.
“Clusters of undervaccinated individuals pose the greatest risk for measles resurgence,”
Independent public-health expert (epidemiologist)
Experts note that targeted interventions — not only broad messaging — will be necessary to reach communities with low uptake and prevent further outbreaks.
Unconfirmed
- Specific drivers for every local outbreak (for example, the precise social networks or events that initiated spread) remain under investigation and not all transmission chains are fully mapped.
- The relative contribution of international importations versus domestic transmission in some clusters has not been definitively established for all outbreaks.
- Long-term trends in vaccine hesitancy versus access-related declines in coverage are still being analyzed; causation at the community level varies by location.
Bottom line
With 2,012 confirmed cases as of Dec. 23, 2025, the U.S. is confronting its highest measles burden in more than three decades. The outbreak pattern reflects concentrated susceptibility in specific communities rather than uniform national decline, meaning targeted vaccination and local public-health measures can still blunt transmission effectively.
Immediate priorities are ensuring easy access to MMR vaccine, reinforcing school-entry vaccination checks, and supporting local health departments with resources for contact tracing and quarantine. Over the medium term, rebuilding routine childhood vaccination coverage to pre-pandemic levels will be essential to reduce the risk of recurrent large outbreaks.
Sources
- ABC News (news report summarizing CDC figures)
- Centers for Disease Control and Prevention (official national case and outbreak data)
- South Carolina Department of Health and Environmental Control (state-level outbreak updates, official)