Lead
The Centers for Disease Control and Prevention reported on Friday that at least 245 new measles cases were added to national totals, bringing the U.S. count to 416 cases across 14 states. The outbreaks span states from Arizona to Washington, with South Carolina facing the largest local surge — 54 new cases added Friday for a state total of 700. Federal data show about 94% of cases are among people who are unvaccinated or whose vaccination status is unknown; only a small share had one or two MMR doses. Health officials warn that declining childhood vaccination coverage is widening the pool of susceptible people and raising the risk of further local surges.
Key Takeaways
- CDC reported 416 measles cases in 14 states as of Friday, with 245 newly reported cases added in the latest update.
- States with cases include Arizona, California, Florida, Georgia, Idaho, Kentucky, Minnesota, North Carolina, Ohio, Oregon, South Carolina, Utah, Virginia and Washington.
- Only three U.S. cases this year were linked to international visitors; most transmission is domestic.
- About 94% of cases occurred in people who were unvaccinated or had unknown vaccination status; 3% had one MMR dose and 3% had two doses.
- The majority of cases are among patients under 19 years old; roughly 2% of reported cases led to hospitalization.
- South Carolina reported 54 new cases Friday, raising its outbreak total to 700; 485 people are in quarantine and 10 are in isolation with the latest quarantine period ending Feb. 14.
- Kindergarten MMR coverage fell to 92.5% in 2024–25, down from 95.2% in 2019–20, increasing the risk of local outbreaks.
Background
Measles is a highly contagious viral disease controlled in the U.S. largely through routine childhood immunization with the measles-mumps-rubella (MMR) vaccine. The CDC recommends two MMR doses—first at 12–15 months and a second at 4–6 years. One dose is about 93% effective against measles, and two doses are about 97% effective, a level that historically suppressed sustained transmission when high coverage was maintained.
Sustained measles elimination in the U.S. has depended on maintaining high vaccination coverage and rapid local responses to imported or community cases. In recent years, several factors—vaccine hesitancy, missed well-child visits during the COVID-19 pandemic, and localized pockets of low coverage—have eroded population immunity in some counties and ZIP codes. Public-health authorities monitor cases, quarantine exposed contacts and use targeted vaccination campaigns to limit spread.
Main Event
The CDC’s latest update on Friday counted 416 measles cases across 14 states after adding 245 newly reported infections. The agency’s tally lists states from the Southwest to the Pacific Northwest, and several southeastern and Midwestern states. Only three of the reported cases were traced to international visitors, indicating that most transmission is occurring within U.S. communities.
South Carolina remains the largest active cluster. The South Carolina Department of Public Health reported 54 new cases on Friday, raising the state total to 700; officials said this is the largest measles outbreak the state has seen in more than 30 years. State health authorities reported 485 people currently under quarantine and 10 in isolation, with the most recent quarantine periods extending through Feb. 14.
Federal data show 94% of national measles cases are among people who are unvaccinated or whose vaccination status is unknown. Only 3% of cases had received a single MMR dose and 3% had two doses. Children and adolescents under 19 comprise the majority of cases, and about 2% of all reported patients required hospitalization for measles-related complications.
Analysis & Implications
Public-health experts say the current rise in measles cases reflects gaps in immunity that have grown since the COVID-19 pandemic disrupted routine pediatric care. When kindergarten and preschool MMR coverage declines even a few percentage points, the number of susceptible children increases cumulatively, creating concentrated pockets—often defined by county or ZIP code—where outbreaks can ignite and spread.
Localized outbreaks can strain hospital and public-health resources. Measles can cause severe complications, including pneumonia and encephalitis, particularly in infants and immunocompromised people, which can result in increased local hospital admissions even when national hospitalization percentages remain low. A surge concentrated in specific communities may therefore produce outsized burdens on nearby hospitals.
Policy and operational responses will likely include intensified vaccination drives, school-based outreach, and targeted quarantine and contact-tracing efforts. If MMR coverage does not recover toward pre-pandemic levels, public-health officials warn that similar clusters will recur and could enlarge, especially in areas already below herd-immunity thresholds typically cited near 95% coverage for measles.
Comparison & Data
| School Year | Kindergarten MMR Coverage (%) |
|---|---|
| 2019–2020 | 95.2 |
| 2023–2024 | 92.7 |
| 2024–2025 | 92.5 |
The table above summarizes federal kindergarten MMR coverage estimates cited by public-health authorities. The decline from 95.2% in 2019–20 to 92.5% in 2024–25 represents a modest percentage drop but a significant increase in the absolute number of unprotected children when applied to the national birth cohort. That larger susceptible population helps explain why localized outbreaks can expand rapidly despite a relatively small national case count.
Reactions & Quotes
“I’m very alarmed by the increase in measles cases in the U.S. over the last year or two,” Dr. Kristin Moffitt, an infectious-disease physician, said, noting the recent tally and the prior year’s surge past 2,000 cases.
Dr. Kristin Moffitt, Boston Children’s Hospital (infectious-disease physician)
Context: Moffitt linked the rise to falling vaccination coverage in specific communities and warned that continued declines could lead to more local surges and hospital admissions.
“As you have lower vaccination rates each year, you’re going to get a bigger and bigger population of people that are not immune,” Dr. Robert Frenck said, stressing the cumulative effect of small declines in coverage.
Dr. Robert Frenck, Cincinnati Children’s Hospital (pediatrics, infectious diseases)
Context: Frenck emphasized that even modest reductions in coverage increase outbreak likelihood and complicate containment efforts.
Unconfirmed
- Whether the current rate of case reporting reflects a true acceleration in transmission versus increased testing and reporting remains unresolved pending further CDC analysis.
- The ultimate trajectory of the 2025 season—whether it will surpass the prior year’s more than 2,000 cases nationally—cannot be predicted with certainty at this stage.
Bottom Line
The CDC’s update that 416 measles cases have been reported in 14 states underscores an ongoing pattern: measles resurges where vaccination coverage dips. Most cases are among unvaccinated or vaccination-status–unknown individuals, and the largest active cluster is in South Carolina with 700 cases reported to date.
Restoring and sustaining high two-dose MMR coverage in young children, combined with timely outbreak response and local vaccination campaigns, remain the most effective strategies to prevent larger, more destructive surges. Public-health agencies will be watching school-entry coverage data and local transmission patterns closely in the coming weeks to guide interventions.
Sources
- ABC News — (national media report summarizing CDC and state updates)
- Centers for Disease Control and Prevention (CDC) — (federal surveillance and guidance)
- South Carolina Department of Health and Environmental Control (SCDHEC) — (state health department outbreak updates)
- Boston Children’s Hospital — (academic and clinical expertise noted in reporting)