Independent
From 15 cases to 1,078
Pennsylvania's health department dates the outbreak to late April in Lebanon County, where the first cases were identified April 23 to 30. It said the source was likely local, not travel. By Oct 7 it had reached 41 of the state's 67 counties.
Pennsylvania measles cases in 2026, running total
CDC's count trails the state's because states report weekly. The department said its Oct 7 jump of 74 cases mostly reflected late reports: more than 40 were people sick more than two weeks earlier, "not … a current surge."
Pennsylvania cases by month reported
Includes 12 earlier, unrelated cases reported January to March.
New York: cases by week, outside New York City
Where vaccination fell short
Health officials say a community is protected when at least 95% of people are vaccinated.
Pennsylvania and New York measure vaccination differently, so their colors use separate scales and can't be compared across the border. Pennsylvania: kindergartners with both MMR doses, 2025–26. New York: children with at least one dose by age 2, as of Jan 1, 2026; the state says its rates may be underestimated. New York City reports 7 cases with no borough breakdown.
Hardest-hit counties
● Community transmission, as Pennsylvania's health department defines it.
The communities, in their own words
Five deaths, all unvaccinated
These are Pennsylvania's first measles deaths since 1991, the department says. Two were infants. The state gives only county and vaccination status; TMI does the same.
Deaths announced by Pennsylvania
Three different death counts
Clinics, and an emergency order
Pennsylvania ran pop-up clinics and urged MMR for babies as young as 6 months in affected communities. New York declared a statewide disaster emergency on Oct 5, letting paramedics, midwives and pharmacists give the vaccine.
MMR doses given in Pennsylvania per month
New York's Executive Order 65
A fight over the dead, and the vaccine
HHS Secretary Robert F. Kennedy Jr. has both urged measles vaccination and questioned Pennsylvania's death reports. In August the president ordered HHS to plan for splitting MMR into three single shots. CDC's own safety page says there is no published evidence of any benefit.
The death-count dispute
The vaccine
The most cases since 1991
CDC counts 3,887 US cases this year as of Oct 1, far above 2025's 2,289. ABC News and CNN report it is the most since 1991. Whether the US has lost its measles elimination status will be decided in November.
US measles cases, 2026 running total
CDC weekly updates. Earlier large outbreaks: West Texas in 2025 (762 cases, two child deaths) and South Carolina from October 2025 to April 2026 (997 cases).
What health agencies say
The basics, as stated by CDC, the World Health Organization and the two states' health departments. This is not medical advice; ask a doctor or your health department.
How we got here
From January 2025, the start of the window PAHO uses to judge the US outbreak chain, to this week. Filter by where it happened.
What the record can't settle yet
Where credible sources disagree, and what would settle each question.
How we built this
Method
Case counts come from the Pennsylvania and New York health departments, New York City's health department and CDC, read on Oct 8, 2026. Where their dashboards can't be downloaded, values were read from the published page and checked against the published totals. County counts are a snapshot; neither state publishes county history.
Vaccination rates come from each state's own school and registry data. The two states measure different things, and this page does not compare them directly. Statements from state, federal and international officials and from independent reporting are labeled separately.
What we leave out
No patient, family, school or exposure location is named. Deaths are described only by county and vaccination status, as Pennsylvania's health department does. Communities are described only in the words officials and community members use.
Map: Natural Earth; US Census cartographic boundaries via us-atlas.