The United States is facing its most severe measles outbreak in over three decades. According to the latest data from the Centers for Disease Control and Prevention (CDC) as of October 8, 2026, 4,080 confirmed cases of measles have been registered in the country this year. This is nearly double the 2,289 cases recorded throughout 2025 and represents the highest annual figure since 1991.
This increase is attributed to 42 active outbreaks spanning 47 jurisdictions. Of the total cases, 4,062 were registered within US jurisdictions, while another 18 cases involved foreign visitors.
Currently, 414 patients have been hospitalized, accounting for approximately 10% of the total confirmed cases. Unvaccinated individuals remain the primary carriers of this crisis, making up 95% of all confirmed cases.
The most affected demographic groups are school-aged children and adolescents aged 5 to 19, who account for 42% of those affected, as well as adults aged 20 and older, representing 40%. The rise in hospitalizations has caused increased concern, as the number has risen to 414, which is about 10% higher than the 244 cases recorded in 2025.
Pennsylvania has become an epicenter of the outbreak, reporting 1,136 cases, 219 hospitalizations, and five deaths this year, marking the largest state-level outbreak in over 30 years. Meanwhile, New York state declared a statewide emergency after registering 108 cases, expanding access to testing and vaccination to curb local spread.
The US CDC emphasizes that measles is a highly contagious respiratory disease that can lead to serious complications such as pneumonia. The Center insists that the MMR vaccine is the best protection, and a population vaccination rate above 95% is necessary to achieve herd immunity.