The United States has recorded 5,182 confirmed measles cases so far in 2026, according to figures published by the Centers for Disease Control and Prevention (CDC). The agency said this is the highest total it has reported since 1991. The disease spreads easily but can be prevented with vaccines.
The CDC data shows the 2026 count is more than double the 2,289 confirmed cases recorded in 2025, with the tally counted through November 2026. The outbreak comes as vaccination coverage among US kindergarteners has fallen.
Children make up most confirmed infections
Children under five account for 18 percent of cases, while those aged five to 19 account for 41 percent. Overall, young people make up about 59 percent of confirmed infections.
Most cases, a total of 4,993, were linked to outbreaks. Kindergarten vaccination coverage has slipped from 95.2 percent in the 2019-2020 school year to 92.4 percent in 2025-2026.
Federal and state death counts diverge
The CDC reports four measles deaths in 2026, a lower figure than the one kept by state officials. Pennsylvania, the state hit hardest by the outbreak, says its Department of Health has recorded six deaths and 1,487 cases this year.
The gap has become a point of contention between Pennsylvania Governor Josh Shapiro and US Health Secretary Robert F Kennedy Jr over how deaths are classified. Pennsylvania counts a death as “measles-associated” if a confirmed case dies within 30 days of symptoms starting, unless an unrelated event caused the death.
In August, Pennsylvania reported that two unvaccinated people had died of measles. The CDC first included those deaths in its national tally but later removed them after Kennedy, a vaccine sceptic, questioned whether measles had caused or contributed to the fatalities. The agency said it is working with the US Council of State and Territorial Epidemiologists to set a standard definition for measles deaths.
Experts warn of wider global consequences
Infectious disease experts warn that the dispute over classification puts the CDC at odds with a long-established way of tracking the effects of measles. Epidemiologists said that counting “measles-associated” deaths has long been a standard used by the World Health Organization and the CDC.
The United States declared the virus eliminated more than two decades ago, yet cases have risen globally, particularly in communities that are sceptical of vaccines or have gaps in healthcare access. Experts warned that falling vaccination in one area can leave people thousands of miles away exposed, making prevention a shared global responsibility.
