Measles Cases in the United States Top 4,000, Far Past Last Year’s Record

Confirmed measles cases in the United States have passed 4,000 so far this year, the Centers for Disease Control and Prevention reported Friday, nearly double last year’s total, which was itself the highest in three decades.

The CDC counted 4,080 cases as of Thursday, compared with 2,289 in all of 2025, CBS News reported. Most states and the District of Columbia have reported at least one case. According to CBS News’s account of the agency’s figures, 95 percent of this year’s patients were unvaccinated or had an unknown vaccination status; about 2 percent had received one dose of the measles, mumps and rubella vaccine and about 2 percent had received two.

The largest outbreak is in central Pennsylvania, where the state Health Department has reported more than 1,000 cases since April, making it the worst single outbreak in the country since the early 1990s, CNN reported, surpassing last year’s outbreaks in Texas and South Carolina. Pennsylvania added 145 cases on Wednesday alone, CBS News reported. The state has recorded five measles-associated deaths this year. Lancaster County is near the center of the outbreak, and Mifflin County has been among the hardest hit.

Many of those affected are Amish and other Plain people, communities that tend to have lower vaccination rates. Doctors at the Central Pennsylvania Clinic, which treats children and adults with genetic disorders common in those communities, told CNN that they had never seen so many patients hospitalized in such a short span. They said lower vaccination among Plain families is not rooted in blanket opposition and that steady, patient advice, without pressure, has been the most effective way to raise coverage.

In neighboring New York, Governor Kathy Hochul declared a disaster emergency on Monday over rising cases, CBS News reported, issuing an executive order that lets more health professionals give measles vaccines and allows nurses to order tests.

The response has also become entangled in politics. Federal and Pennsylvania officials have clashed over how measles deaths are defined and announced, disputes that CNN reported have disrupted public health planning. Pennsylvania counts a death as measles-associated when a person with a lab-confirmed infection dies within 30 days of symptoms and the death is not from an unrelated cause, CBS reported.

The science on prevention is not in dispute. One dose of the MMR vaccine is about 93 percent effective against measles and two doses about 97 percent, with lifelong protection, and extensive research supports its safety. Yet the share of parents exempting kindergartners from required vaccines reached a record last school year, CNN reported.

Parents who hesitate often cite a wish to make their own medical decisions and distrust of official messaging, concerns doctors say are best met with respect and repeated, consistent advice. Symptoms usually appear one to two weeks after exposure, starting with high fever, cough, runny nose and red, watery eyes, followed days later by a rash.