Pennsylvania’s measles outbreak, with over 1,000 cases, has surpassed records not seen since 1991, making it the largest since the US declared the disease eliminated in 2000. The tally includes 207 hospitalizations and five deaths, all in unvaccinated individuals.

Health officials reported 1,078 cases as of this afternoon, with 12 cases recorded in January and March. The outbreak began in April and has seen 34 new infections since Monday.

With the US facing slipping vaccination rates, the resurgence of measles is a stark reminder of the importance of vaccines. Pennsylvania’s current outbreak far exceeds the previous record holder, South Carolina, with 1,066 cases compared to 997.

Experts from the Pan American Health Organization (PAHO) will review data in November regarding the US's status as a measles-free country, with widespread expectations that the US has lost this status. Canada lost its elimination status in 2025, highlighting the global nature of the challenge.