The United States has seen a sharp rise in measles cases in 2025. New data from the Centers for Disease Control and Prevention (CDC) shows about 1,912 confirmed infections so far this year. This is a major increase compared with the 285 cases reported in 2024.
Federal and state health departments have identified 47 outbreaks in different parts of the country. The rapid growth in cases has renewed concern about falling vaccination rates and the vulnerability of communities where immunization levels are low.
Current Hotspots Across the Country
Several states are dealing with active transmission:
- South Carolina has the largest cluster with more than 110 confirmed cases. Most infections are linked to schools, daycare centers and community events.
- Health officials along the Utah and Arizona border are reporting ongoing spread within close-knit communities.
- States including Connecticut, California and New York have reported new cases connected to international travel.
Why Measles Is Increasing
Health experts point to a combination of factors:
1. Lower Vaccination Coverage
Some regions have MMR vaccination rates below the level needed to prevent outbreaks. Even small pockets of unvaccinated individuals can allow measles to spread quickly.
2. International Travel
Individuals returning from countries where measles is circulating often bring the virus back to the United States. This can lead to outbreaks in areas with lower vaccination rates.
3. High Contagiousness
Measles can stay in the air for up to two hours in an enclosed space. An infected person can spread the virus to about 90 percent of unvaccinated people who come in contact with them.
What Parents Need to Know About Measles
Measles often begins with symptoms that resemble a severe viral illness. Parents should look for:
- High fever
- Cough, runny nose and red eyes
- Small white spots inside the mouth
- A red rash that spreads from the face to the rest of the body
Young children, pregnant women and immunocompromised individuals are at higher risk for complications. These can include pneumonia, ear infections and, in rare cases, brain inflammation.
When to Seek Medical Care
Parents should contact a healthcare provider if a child has:
- A fever and rash after possible exposure
- Trouble breathing
- Unusual sleepiness
- Dehydration or a fever that does not improve
If seeking medical care, call ahead to avoid exposing others in waiting areas.
Importance of the MMR Vaccine
Health officials continue to emphasize the importance of the MMR vaccine. One dose provides about 93 percent protection. Two doses provide about 97 percent protection.
Children typically receive their first dose at 12 to 15 months of age and the second dose between 4 and 6 years. Catch up vaccination is recommended for older children and adults who missed their scheduled doses.
Communities with high vaccination rates are better protected against large outbreaks.
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