CDC reports 4,588 measles cases as US outbreak continues

The U.S. Centers for Disease Control and Prevention reported 4,588 measles cases as of October 22, 2026, more than double 2025's total. Pennsylvania remains the epicenter with over 1,330 cases and five deaths, heavily impacting low-vaccination Amish communities in Lancaster and Mifflin counties. Nationally, 96% of cases occurred among unvaccinated or status-unknown individuals. In response, New York declared a disaster emergency while Pennsylvania surged vaccination efforts.

National US measles statistics and demographics

• ▪According to CDC data through October 22, 2026, nationwide measles-related hospitalizations in the United States stood at 479
• ▪CDC demographic data through October 22, 2026, shows that children and teenagers aged 5 to 19 constituted the largest age group affected by measles at 1,914 cases, or 42% of all reported cases
• ▪The U.S. Centers for Disease Control and Prevention reported 4,588 measles cases across the United States as of October 22, 2026, an increase of 178 cases from the previous week
• ▪The total of more than 4,580 U.S. measles cases reported by October 22, 2026, is more than double the number of cases recorded in the United States for the whole of 2025

Pennsylvania outbreak statistics and response

• ▪The U.S. Centers for Disease Control and Prevention announced plans to deploy additional support to Pennsylvania to assist state health officials in investigating the measles outbreak in Pennsylvania
• ▪The Pennsylvania Department of Health reported at least 1,338 confirmed measles cases across 44 counties as of October 23, 2026, with more than 250 hospitalizations and five deaths
• ▪The U.S. Centers for Disease Control and Prevention confirmed three measles-associated deaths in Pennsylvania in 2026, whereas the state health department reported five deaths
• ▪Pennsylvania healthcare providers administered over 39,000 measles vaccines during the first three weeks of October 2026, compared to a monthly state average of 25,000 vaccines

Impact on Pennsylvania local communities

• ▪Local Amish communities with low vaccination rates in Pennsylvania's Lancaster and Mifflin counties were impacted most heavily by the state's 2026 measles outbreak
• ▪Pennsylvania Secretary of Health Dr. Debra Bogen held a roundtable on October 22, 2026, with Mifflin County healthcare providers to evaluate local public health needs during Pennsylvania's measles outbreak
• ▪Three of the five individuals who died from measles in Pennsylvania during 2026 resided in Lancaster County

State-level outbreaks in Utah and New York

• ▪New York Governor Kathy Hochul declared a disaster emergency in October 2026 following a rise in measles cases that reached over 160 confirmed cases statewide by October 20, 2026
• ▪Utah reported over 700 measles cases in 2026 as of October 20, 2026, though state health officials reported no new diagnoses during the three weeks prior to October 20

Vaccine effectiveness and nationwide status

• ▪According to CDC data, 96% of individuals who contracted measles in the United States in 2026 were unvaccinated or had an unknown vaccination status
• ▪According to the CDC, two doses of the measles, mumps, and rubella (MMR) vaccine are nearly 97% effective against measles, while a single dose is about 93% effective