Measles Resurgence

This week we talk about polio, malaria, and smallpox.
We also discuss vaccines, the CDC, and the HHS.
Recommended Book: Remnant Population by Elizabeth Moon
Transcript
In 2000, the United States declared measles eliminated. That didn’t mean nobody in the country would ever catch it again, it meant the virus was no longer freely spreading within the US. New cases generally arrived with someone who had been infected elsewhere, and public health workers were able to stop those cases from turning into long-running chains of transmission via the systems, tools, and infrastructure they created.
In early October of 2026, Pennsylvania reported more than a thousand new measles cases this year, most of them part of an outbreak that began in April. As of October 7, the state had confirmed 1,078 cases across 41 counties, 207 hospitalizations, and five measles-associated deaths. Nationally, the Centers for Disease Control and Prevention, the CDC, had counted nearly 3,900 cases through the beginning of the month, making this the worst year for measles in the US in decades.
Pennsylvania’s latest update included 74 newly confirmed cases, though the state was careful to say that more than 40 of those people had become sick over two weeks earlier. So these were newly *reported* cases, not necessarily newly *infected* people—a distinction that matters when we’re trying to figure out whether an outbreak is speeding up or slowing down.
There’s a similar distinction being made with the death figures. Pennsylvania calls its five deaths *measles-associated*, using a definition that considers timing, a confirmed infection, medical evidence, and whether an unrelated cause might explain the death. The CDC’s national death count has not always matched the state’s, in part because the agencies publish on different schedules and review and tally deaths differently; so reporting on these sorts of things can sometimes be unintentionally fuzzy due to varying definitions and numbers.
What I’d like to talk about today is what it actually means to eliminate a disease, how measles has managed to claw its way back in a country that achieved that ‘eliminated’ milestone more than a quarter-century ago, and how vaccination, misinformation, and changing federal policy might shape what happens next.
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There are a few words public health workers and officials use that sound similar, but which describe substantially different achievements.
If a disease has been *eradicated*, it no longer circulates naturally anywhere in the world, as is the case with smallpox. The last known natural case was recorded in Somalia in 1977, and the World Health Organization declared the disease eradicated in 1980. There have been no natural smallpox outbreaks since. That’s a truly remarkable global achievement, and it’s why routine smallpox vaccination isn’t necessary for most people today.
*Elimination* is more local, and more conditional. It means sustained transmission of a disease has been interrupted in…