The US has recorded 4,410 measles cases in 2026, with falling vaccination coverage leaving hundreds of thousands of children vulnerable and Pennsylvania accounting for more than 1,200 infections.
The United States has recorded 4,410 measles cases so far in 2026, according to the Centres for Disease Control and Prevention, as the outbreak continues to spread across the country and federal officials send additional help to the hardest-hit state.
The CDC said the latest count marked an increase of 330 cases in one week and included 451 measles-related hospitalisations. Children and teenagers aged five to 19 make up the largest share of infections at 42%, followed closely by adults aged 20 and over at 41%, while 17% of cases have been among children under five.
Pennsylvania remains the epicentre of the outbreak. The state health department said it had logged 1,222 cases across 42 counties by Wednesday, up by 86 since October 9. Officials there said the outbreak has led to 225 hospitalisations and five confirmed measles-associated deaths, while a sixth reported death is still under investigation.
In response, the CDC has dispatched an investigator from its Epidemic Intelligence Service to Pennsylvania under an emergency assistance request known as an Epi-Aid. State officials have also stepped up vaccination efforts, saying health centre staff have given more than 5,900 doses of the measles, mumps and rubella vaccine at 202 pop-up clinics since the outbreak began in late April.
The wider public health picture has also worsened as vaccination rates fall. CDC data show measles coverage among US kindergarteners declined from 95.2% in the 2019-20 school year to 92.4% in 2025-26, leaving an estimated 280,000 children at risk because of gaps in protection. In New York, Governor Kathy Hochul declared a statewide disaster emergency on October 5 in response to rising cases nearby in Pennsylvania, a move that broadened the number of health workers allowed to give vaccines and gave nurses more flexibility to order measles testing.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
