US Measles Cases Top 5,000, the Highest Count in 35 Years

The US Centers for Disease Control and Prevention (CDC), the country's main public health agency, says 5,182 measles cases have been confirmed nationwide so far in 2026. It is the highest figure since 1991. Measles is highly contagious but preventable with a vaccine, and the rise comes as vaccination coverage has slipped.

Who is affected

Children and teenagers account for roughly 59 percent of confirmed cases. Children under five make up 18 percent, while those aged five to 19 make up 41 percent. Most cases, 4,993, were linked to outbreaks.

Last year the US recorded 2,289 confirmed cases, so this year's total is more than double. Over the same period, vaccination coverage among American kindergarteners fell from 95.2 percent in the 2019-2020 school year to 92.4 percent in 2025-2026.

Dispute over deaths

According to CDC data, four people have died of measles in 2026. That is fewer than state officials have reported, notably in Pennsylvania, the state hit hardest by the outbreak. Pennsylvania's Department of Health reports six deaths and 1,487 cases this year.

The federal count is at the centre of a dispute between Pennsylvania Governor Josh Shapiro and US Health Secretary Robert F Kennedy Jr over how deaths are classified. Pennsylvania counts "measles-associated" deaths, meaning a person with confirmed measles who dies within 30 days of symptoms appearing, unless an unrelated event caused the death.

In August, Pennsylvania reported that two unvaccinated people had died of measles. The CDC first added them to its national tally, then removed them after Kennedy, a vaccine sceptic, questioned whether measles had caused or contributed to the deaths. The CDC says it is working with the Council of State and Territorial Epidemiologists to create a standard definition of measles deaths.

Infectious disease experts warn that the dispute puts the CDC at odds with a long-established approach to tracking measles. Epidemiologists told Al Jazeera that counting "measles-associated" deaths has long been a standard for both the World Health Organization and the CDC.

The US declared measles eliminated more than two decades ago. Cases have also risen globally, particularly in vaccine-sceptical communities or places with gaps in healthcare access.