The U.S. recorded its first measles-related deaths in 35 years this week after two Pennsylvania residents died from the disease, federal health officials said on Tuesday. The fatalities follow a surge in cases that has pushed total confirmed infections to 2,777 nationwide in 2026, the highest annual tally since the pre-vaccine era, according to the Centers for Disease Control and Prevention.
The two deaths mark the first in Pennsylvania from measles since the late 1990s, officials said. Nationally, July 2026 saw the highest monthly case count in 35 years, with 94% of confirmed cases—2,614 out of 2,777—linked to outbreaks. Of those, 1,239 cases stemmed from outbreaks that began in 2026, while 1,375 originated from outbreaks that started in 2025. The CDC reported 169 hospitalizations and two deaths in 2026 to date, compared with 243 hospitalizations and three deaths in 2025.
Health authorities estimate that about one in five unvaccinated individuals who contract measles will require hospitalization. The virus is highly contagious, with up to 90% of unvaccinated people nearby becoming infected after exposure. Symptoms typically appear 10 to 21 days after contact, and health experts recommend a 21-day quarantine for unvaccinated individuals exposed to the disease. The measles virus can remain airborne for up to two hours.
Vaccination coverage among kindergarteners has declined from 95.2% in the 2019–2020 school year to 92.7% in 2023–2024, falling short of the 95% threshold required for herd immunity. A Texas county at the center of a 2025 outbreak had a kindergarten vaccination rate of just 80% in 2023–2024. Two doses of the MMR vaccine provide 97% protection against the virus, while adults born before 1957 are presumed immune due to likely childhood exposure.
Before the measles vaccine became widely available in 1963, the U.S. recorded 3 to 4 million cases annually, leading to 48,000 hospitalizations and 400 to 500 deaths each year. The current outbreak has renewed scrutiny of vaccine hesitancy, including long-debunked claims linking the measles vaccine to autism, which originated from a retracted 1998 study by British researcher Andrew Wakefield involving 12 children.
