1,398 cases, and the vaccine queue doubled

Pennsylvania’s health department said on Wednesday that 1,398 measles cases have been confirmed in 44 of the state’s counties so far this year, 38 of them since Monday¹. There have been 265 hospitalisations and five measles-associated deaths¹. Only four cases, under 1%, were in vaccinated people¹. Desk arithmetic: about one case in five has needed a hospital.

Across the United States, the CDC counted 4,588 confirmed cases this year as of 22 October, with 43 new outbreaks². For the whole of 2025 the figure was 2,289². Desk arithmetic: with two months still to go, this year’s count is already about twice last year’s. The CDC’s explanation is not mysterious: kindergarten MMR coverage has slipped from 95.2% in 2019–20 to 92.4% in 2025–26, below the 95% that keeps measles from spreading, which leaves about 280,000 children at risk².

Now the part that does not make headlines. In a typical month, Pennsylvania’s doctors and pharmacies give about 25,000 doses of MMR vaccine¹. In September they gave more than 56,000, and in the first three weeks of October more than 53,000¹. State nurses have run 229 pop-up clinics in the affected communities since late April¹. About 300 health department staff are working with residents and providers, and the state’s measles team meets the CDC’s team every other week to go through cases¹.

That is what a response looks like when it works: dashboards updated, clinics set up where the cases are, doses counted. It is slow, and a month of queues does not undo years of slipping coverage. It is still the right direction.

If you are not sure whether you had two doses, look for your record or ask your doctor; Pennsylvania’s advice is that people with two documented doses need no more, and adults with one dose or no records should talk to a clinician¹. Two doses are 97% effective¹. Measles is not seasonal, but it travels well in holiday crowds².