The United States has now recorded about twice as many measles cases this year as it did in all of 2025. The Centers for Disease Control and Prevention (CDC) counted 4,588 confirmed cases as of Oct. 22, up 178 from the week before. The agency reported 2,289 cases for all of 2025 1.
Last week's total was 4,410 cases, which was up 330 (8.1%) from the week before that 2. Measles is a highly contagious virus that can cause pneumonia, brain swelling and death.
Who is getting sick
The CDC says 479 patients, or 10%, have been hospitalized. That is up 28 from a week earlier 1. Children under 5 are hit hardest: 16% of them (119 of 766) were hospitalized 1.
About 96% of 2026 patients were unvaccinated or had an unknown vaccination status. Only 2% had one dose of the MMR (measles, mumps and rubella) vaccine, and 2% had two 1. Outbreaks account for 96% of cases 1.
The CDC lists three measles deaths this year, and says that count is subject to change as reviews are completed 1. Pennsylvania's local health officials have reported six measles-related deaths and at least 1,200 cases in that state's outbreak 3.
Vaccination rates are slipping
Kindergarten MMR coverage fell from 95.2% in the 2019-2020 school year to 92.4% in 2025-2026. That leaves about 280,000 kindergartners at risk 1. The CDC says its count covers only confirmed cases reported to it, so the true number may be higher 1.
At Pennsylvania's request, the CDC is sending an Epi-Aid team, a short-term field team of disease investigators, to help the state respond 3. A CDC spokesperson said Pennsylvania "has formally requested CDC assistance through the Epi-Aid program" 3.
The fact that we're deploying federal disease detectives to investigate measles outbreaks in 2026 is pretty extraordinary.
The political fight
Health Secretary Robert F. Kennedy Jr. has blamed the pandemic. He said the outbreak is occurring "because so many people went unvaccinated during the COVID pandemic" 3.
Pennsylvania Gov. Josh Shapiro, a Democrat, has blamed Kennedy's messaging. In August, after two unvaccinated people in Lancaster County died, he said Kennedy's post was "inaccurate and misleading" 4. He also said Kennedy told him it would be better if the state went back to "natural measles" 4. The account of that phone call is Shapiro's. Kennedy's side of it is not in the reports we reviewed.
The correlation is clear: Secretary Kennedy has stoked confusion amongst parents and others
What happens next
The CDC updates its measles count weekly, so new totals are expected. Whether the Pennsylvania outbreak slows may depend on how many families get vaccinated in coming weeks.
That matters because the public health agencies that track and fight outbreaks answer to Kennedy. His department's leader is now publicly arguing with a governor over an outbreak, while the national count keeps climbing. Voters will decide Nov. 3 who controls Congress, which oversees those agencies.
The Record
Sources
- Contagion Live, “Measles Update: October 23, 2026” (2026-10-23). contagionlive.com/view/measles-update-october-23-2026
- Contagion Live, “Measles Update: October 16, 2026” (2026-10-16). contagionlive.com/view/measles-update-october-16-2026
- ABC News, “More than 4,400 measles cases reported in US as CDC plans to send 'disease detective' to Pennsylvania” (2026-10-16). abcnews.com/Health/4400-measles-cases-reported-us-cdc-plans-
- Mediaite, “PA Gov. Shapiro Fires Back at RFK Jr's Vaccine 'Thoroughly Discredited' Claims Amid Measles Outbreak in His State” (2026-08-26). mediaite.com/media/news/pa-gov-shapiro-fires-back-at-rfk-jrs
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