Follow-up: U.S. Measles Cases Rise to 4,852, Up 264 in a Week and More Than Double the 2025 Full-Year Total, With 43 Outbreaks Reported
The U.S. Centers for Disease Control and Prevention (CDC) updated its national measles data on October 30: as of noon on October 29, jurisdictions had reported a cumulative 4,852 confirmed measles cases in the United States in 2026, up 264 from the previous update of 4,588 a week earlier and already more than double the 2,289 cases reported in all of 2025.
Of the 4,852 cases, 4,834 were reported by 47 jurisdictions and 18 were among international visitors to the United States. The CDC counts 43 new outbreaks reported in 2026, with an outbreak defined as three or more related cases, and says 96 percent of confirmed cases (4,666 of 4,852) are outbreak-associated: 3,282 from outbreaks that started in 2026 and 1,384 from outbreaks that started in 2025.
The CDC currently confirms three measles deaths in 2026, a number it says is subject to change as reviews are completed. By comparison, 2025 saw 2,289 confirmed cases and 48 outbreaks, with 90 percent of cases outbreak-associated.
Vaccine coverage continues to slip. CDC data show MMR (measles, mumps and rubella) coverage among kindergartners fell from 95.2 percent in the 2019-2020 school year to 92.4 percent in 2025-2026, leaving approximately 280,000 kindergartners at risk during the 2025-2026 school year. Measles was declared eliminated in the United States in 2000, and the CDC says two doses of MMR vaccine are about 97 percent effective at preventing measles.
The CDC notes that its page counts only confirmed cases notified by jurisdictions, not probable cases, that states hold the most up-to-date local information, and that 2025-2026 case counts are preliminary and subject to change.
Related: Follow-up: U.S. Measles Cases Rise to 4,588, Up 178 in a Week, Hospitalizations Reach 479
Source: GSM · USA (original Chinese edition)
Photo: 图：美国疾病控制与预防中心（CDC）总部大楼（GSM联邦固定图库）。 / Image: Headquarters of the U.S. Centers for Disease Control and Prevention (CDC) (GSM federal fixed-image library).
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