Measles Cases Surge Nationwide, Pennsylvania Leads with Over 1,300 Infections

More than 4,580 measles cases have been reported in the United States since Oct. 22, 2026, more than double the total recorded in 2025 and marking the country’s worst resurgence in decades. The CDC says 96 % of those infected were unvaccinated or had unknown vaccination status. Pennsylvania bears the brunt, with 1,338 confirmed cases spread across 44 counties, 21 new cases reported on Oct. 21, over 250 hospitalizations and five deaths, three of which occurred in Lancaster County’s Amish community, which traditionally has low vaccination rates. State health officials say the outbreak is prompting a surge in demand for the measles‑mumps‑rubella (MMR) vaccine. In the first three weeks of October, more than 39,000 doses were administered statewide, well above the usual monthly average of 25,000. Two doses of MMR are about 97 % effective, while a single dose offers roughly 93 % protection. Pennsylvania Secretary of Health Dr. Debra Bogen held a round‑table with providers in Mifflin County to tailor the public‑health response, emphasizing the need to listen to front‑line workers. Similar spikes have been recorded elsewhere: New York Governor Kathy Hochul declared a disaster emergency after the state logged over 160 cases; Utah reported more than 700 infections but has seen no new cases in the past three weeks; South Carolina’s outbreak, which had reached 997 cases earlier this year, was declared over in April. ## Context Measles spreads easily through airborne droplets and can cause serious complications, especially in unvaccinated populations. High‑coverage vaccination remains the most reliable way to halt outbreaks and protect vulnerable groups.