Two measles deaths reported in Pennsylvania as officials urge vaccination

Why measles is back on the radar

Health authorities across the United States have tracked a steady rise in measles cases this year, with outbreaks reported in several states where childhood vaccination rates have fallen below the threshold needed to prevent community transmission. Pennsylvania has recorded a small but growing cluster of infections, including cases in Lancaster County.

Measles is one of the most contagious viruses known to medicine. It spreads through respiratory droplets and can linger in the air for up to two hours after an infected person leaves a room. Before vaccines became widely available in the 1960s, the disease killed an estimated 2.6 million people worldwide each year.

Complications can be severe, especially in young children, older adults, and people with weakened immune systems. They include pneumonia, brain swelling, and, in rare cases, a fatal neurological disease that develops years after the initial infection. About one in five unvaccinated people who contract measles ends up in the hospital, according to federal health data.

How the MMR vaccine works

The two-dose measles, mumps, and rubella (MMR) vaccine is roughly 97 percent effective at preventing infection and has been used safely for decades. Public health experts say a vaccination rate of about 95 percent in a community is enough to stop the virus from spreading through what is known as herd immunity.

Bogen's department has been working with county health offices, pediatricians, and community organizations to set up mobile vaccination clinics and to translate outreach materials into Spanish and other languages spoken in affected neighborhoods. State officials have also expanded a hotline for residents with questions about vaccine access.

The deaths come as Pennsylvania, like several other U.S. states, debates whether to tighten school vaccination rules. Current state law allows parents to opt their children out of required vaccines for medical, religious, or philosophical reasons, and exemption rates have crept upward in recent years.

What state and federal authorities are doing

The Associated Press Health and Science Department has received support from the Howard Hughes Medical Institute's Science and Educational Media Group for its coverage of infectious disease. Federal authorities at the Centers for Disease Control and Prevention have also been in contact with Pennsylvania officials and are monitoring the outbreak, according to people familiar with the response.

Public health experts stress that the deaths are a warning sign rather than an isolated event. With international travel resuming and school classes about to begin, the risk of further transmission is expected to rise in the coming weeks unless vaccination campaigns reach more people quickly.