Health
Measles Outbreaks Surge Nationwide: What to Know
Health Points
- Measles cases in the U.S. are at a 33-year high, affecting over 1,560 people across 41 states.
- Most infections are among unvaccinated or unknown vaccination status individuals, with several outbreaks sending students into quarantine.
- Vaccination rates have dipped below the level needed for community protection, putting the nation’s measles elimination status at risk.
Recent months have seen measles outbreaks emerge in states like Utah, Minnesota, Michigan, Ohio, and South Carolina, with hundreds of children entering quarantine.
Measles spreads quickly, especially among those without vaccination, and public health experts are sounding the alarm about renewed risks.
Why Are Measles Outbreaks Happening?
Experts define a measles outbreak as three or more cases within one area in a month.
Last week, South Carolina recorded its 11th case of 2025, while more than 150 unvaccinated students were quarantined after exposure.
“What this new case tells us is that there is active unrecognized community transmission of measles,” said Linda Bell, MD, with the South Carolina Department of Public Health.
The highly infectious virus has seen 27 percent of cases in children under age five and 39 percent in those ages five to nineteen this year, according to CDC data.
Over 90 percent of cases involve people who are either unvaccinated or whose vaccination status is unknown.
Measles is considered the most contagious virus known to humans, and declining vaccination rates have fueled the recent outbreaks.
The two-dose MMR vaccine is 97 percent effective at preventing measles, but the vaccination rate among U.S. kindergarteners has dropped to 92.5 percent.
Public health authorities warn that if these trends continue, the U.S. could lose its official measles elimination status.
“Eradication means not having sustained transmission for 12 months,” says Catherine Troisi, PhD, an infectious disease epidemiologist at UTHealth Houston.
“We’ve seen continued transmission of measles since the beginning of the year, combined with a weakening of the national vaccination infrastructure and inconsistent, often times unscientific, messaging around vaccination, and I think barring a miracle, the U.S. will lose its elimination status,” says Mathew Kiang, ScD, Stanford University.
How Vaccination Prevents Serious Illness
Many people underestimate measles, not realizing that severe complications are possible.
“While most children who get measles survive, 1 in 5 who are unvaccinated are hospitalized, and 1 in 1,000 will get encephalitis,” explains Dr. Troisi. “It can also cause hearing loss. Before widespread vaccination, measles was the No. 1 cause of deafness among children. Plus, three people have died this year from measles.”
No antiviral medication exists for measles, but most people recover within about 10 days with rest, nutritious food, and enough fluids to stay hydrated.
Even short cases can be especially uncomfortable, bringing symptoms like high fever, hacking cough, a blotchy rash, watery eyes, diarrhea, and ear infections.
Protection through immunization is essential. “The MMR vaccine is safe and effective and is by far the best way to protect yourself and others you love from measles,” Dr. Kiang emphasizes.
Staying informed—and up to date with your immunizations—remains the strongest defense against measles and its complications. Consult with your healthcare provider about recommended vaccinations for you and your family.
