What to know about measles in Pennsylvania
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Illustration: Brendan Lynch/Axios
Pennsylvania measles cases are on track to eclipse last year as infections rise nationwide.
Why it matters: The state has so far avoided a major outbreak this year, but falling vaccination rates are clearing a path for one of the world's most contagious viruses to make a comeback.
By the numbers: The Pennsylvania Department of Health has confirmed 12 cases in the first two months of this year — all in Lancaster, Montgomery and Chester counties — putting the state on pace to surpass the 16 infections reported statewide last year. All cases were among unvaccinated residents, per the department.
- The state has more than doubled its case count since mid-February.
- Pennsylvania had six reported cases in 2024.
- There are no reported cases in Allegheny County, which hasn't seen a case since 2019.
Flashback: Last year, U.S. measles cases topped 2,000 for the first time in over 30 years, per CDC data.
The big picture: Declining vaccination rates have contributed to an increase in measles cases, placing the U.S. at risk of losing its long-standing elimination status.
- The drop, linked in part to backlash against pandemic-era health mandates and politically influenced hesitancy, has left some Americans more susceptible to outbreaks.
Zoom in: More than half of Pennsylvania's counties, including Allegheny County, don't meet the herd immunity threshold for measles.
Threat level: Measles is highly contagious, spreads easily through the air and can linger indoors for hours, per the CDC. Infection can raise the risk of pneumonia or inflammation of the brain or lungs, particularly in young children.
- Symptoms include high fever, rash, cough and pink eye.
State of play: Getting two doses of the MMR or MMRV shot is safe and 97% effective at preventing infections, per the CDC.
The bottom line: Public health departments, including in Allegheny County, are starting to launch targeted campaigns to combat vaccine hesitancy and reverse declining rates.