US measles cases hit 4,852, more than double all of 2025

The U.S. has confirmed 4,852 measles cases so far in 2026, according to the Centers for Disease Control and Prevention, with data as of Oct. 29. That is more than double the 2,289 cases reported in all of 2025. In 2024 the count was 285.

The CDC counts 43 new outbreaks this year. Of all confirmed cases, 96% are tied to outbreaks. Cases have come from 47 jurisdictions. The agency lists 3 deaths this year and says that number may change as reviews finish.

Measles was declared eliminated in the U.S. in 2000 because so many people got vaccinated, the CDC says.

Where it is worst

Pennsylvania has the most cases of any state. The state has more than 1,350 cases this year, and more than a third are in Lancaster County, the Associated Press reported Oct. 30. The AP called it the nation’s worst measles outbreak in 35 years. Community leaders told the AP the real count is higher, since many sick people never see a doctor.

Lancaster County is home to the largest Amish population in the U.S. The outbreak has hit Amish and conservative Mennonite communities hard. A 2022 survey by Franklin & Marshall College found about 3 in 10 Amish families reported vaccinating their children, the AP reported.

The Pennsylvania Department of Health reported 225 hospitalizations and 5 deaths linked to measles as of Oct. 14. Only 4 of the state’s cases were in vaccinated people, less than 1%.

Cases in Pennsylvania have come down from a September peak. Some doctors expect them to rise again as winter moves gatherings indoors, the AP reported.

The vaccine gap

The CDC says 92.4% of U.S. kindergartners got their required MMR shots in the 2025 to 2026 school year. That is down from 95.2% in 2019 to 2020. The drop leaves about 280,000 kindergartners at risk, the agency says.

When more than 95% of a community is vaccinated, most people are protected, according to the CDC. Pennsylvania’s kindergarten rate fell to 93.2% last year. Lancaster County’s rate is 88%, according to an AP review of state data.

Some families are now coming in for shots. One clinic network in Lancaster County has given about 450 measles shots at small clinics for Plain communities, its chief medical officer told the AP. Clinics there also offer infants their first dose earlier than the usual schedule, as experts advise in outbreak areas.

What it means for you

Two doses of the measles, mumps and rubella vaccine are 97% effective at preventing measles, the CDC says. One dose is 93% effective. About 10% of infections are breakthrough cases in vaccinated people, most often in communities with an active outbreak.

Measles spreads through the air. You can catch it just by being in a room where an infected person has been. Most cases are mild, but it can cause pneumonia and brain swelling. Before the vaccine, measles put about 48,000 Americans in the hospital and killed 400 to 500 each year, according to the CDC.

If you are not sure you had two doses, your doctor or state immunization registry can check. Families in or traveling to outbreak areas can ask their pediatrician about an early dose for babies.

The national count still grows every week. The CDC posts new numbers weekly.