US measles cases exceed twice the 2025 tally

The CDC reported 178 additional measles cases in a week, bringing the 2026 national tally to 4,588 across at least 43 outbreaks—more than double the 2025 total. [4] Pennsylvania's outbreak has caused at least six deaths, including two infants; state authorities said none of those who died was vaccinated. [2] Why it matters: Pennsylvania illustrates the consequences behind the national count: at least 251 people have been hospitalized, roughly one in five reported cases. Officials identify low vaccination rates, particularly in affected Amish communities, as the biggest containment challenge. [2] Key insights: The Pennsylvania outbreak began in late April and is the state's largest in more than three decades. [2] | People aged 18–49 account for about 800 Pennsylvania cases, showing that this outbreak is not confined to children. [2] | University of Maryland researcher Braxton Mitchell says large households and frequent communal gatherings create opportunities for rapid transmission in Amish communities. [2] | The national increase comes amid criticism of CDC transparency and changes to vaccine infrastructure under Health Secretary Robert F Kennedy Jr; the evidence does not quantify their contribution to transmission. [4] Cheatsheet facts: What happened: The US reported 4,588 measles cases in 2026 as of Friday, including 178 newly reported cases that week. [4] | Why: Pennsylvania officials cite low vaccination rates as their biggest challenge; researchers also point to frequent close contact within affected Amish communities. [2] | Who pays: Pennsylvania has recorded at least six deaths and 251 hospitalizations; two of those who died were infants. [2] | The catch: Mitchell describes skepticism toward government intervention in affected Amish communities, complicating efforts to increase protection. [2]