U.S. Faces Severe Measles Outbreak, Focuses on Vaccination

The United States is dealing with its most severe outbreak of measles in decades. The situation is particularly acute in Pennsylvania. According to the U.S. Centers for Disease Control and Prevention (CDC), there have been over 4,580 cases nationwide since October 22, more than doubling the total number for the entirety of 2025. Of these cases, 96% are either unvaccinated or have unknown vaccination status.

Pennsylvania has confirmed at least 1,338 measles cases spanning 44 counties this year. This includes 21 new cases reported as of October 21. The Pennsylvania Department of Health reported that more than 250 individuals have been hospitalized, and five have died. The state emphasizes the urgent need for vaccination, particularly in communities like the Amish in Lancaster and Mifflin counties, which exhibit low vaccination rates. Three of the deceased were residents of Lancaster County.

In response, Pennsylvania Secretary of Health Dr. Debra Bogen convened a meeting with healthcare providers in Mifflin County. This roundtable aimed to refine the state’s public health response by incorporating insights from those directly involved in managing the outbreak. Dr. Bogen emphasized the importance of on-ground experiences in formulating effective solutions.

Health officials advocate vaccination as the best defense against measles. While two doses of the measles, mumps, and rubella (MMR) vaccine are nearly 97% effective, even a single dose offers about 93% efficacy according to the CDC. Encouragingly, interest in vaccination is rising. Pennsylvania’s health department reported over 39,000 measles vaccinations in the first three weeks of October alone, exceeding the state’s typical monthly average of 25,000.

This outbreak is not limited to Pennsylvania. New York has also seen a significant rise in measles cases. Governor Kathy Hochul declared a disaster emergency earlier this month due to these rising numbers. As of October 20, New York confirmed over 160 cases. Utah is experiencing similar issues, with over 700 measles diagnoses reported. However, the Utah Department of Health and Human Services noted no new diagnoses in the past three weeks.

South Carolina previously faced a measles outbreak that concluded in April. This year, the state registered at least 997 cases, according to the South Carolina Department of Public Health.