The United States recorded 2,318 confirmed measles cases by late July 2026, exceeding the 2025 total of 2,289—the previous high since 1991. This marks a second consecutive year of record-breaking transmission and intensifies pressure on a public health system already grappling with the virus’s steady re-establishment. The country eliminated endemic measles in 2000, but sustained outbreaks over the past 18 months now threaten that status.

The resurgence is fuelled by declining MMR vaccination coverage. National kindergarten vaccination rates slipped to 92.5% in the 2024–25 school year, down from 95.2% in 2019–20 and below the 95% threshold needed to interrupt community spread. In some outbreak clusters, rates have fallen to 20%. The CDC reports that 93% of cases are in unvaccinated individuals or those with unknown status. Official tallies are likely undercounts: modelling work in Utah suggests a large border outbreak may be three to four times larger than reported, and South Carolina health officials acknowledge their 997-case total is incomplete.

Outbreaks have flared in 43 states and the District of Columbia. The largest, centred in South Carolina, Utah, and Arizona, have sickened hundreds; Virginia and Pennsylvania are managing newer waves. Last year’s Texas outbreak caused two child deaths and one adult fatality—the first US measles deaths in a decade. The federal response has drawn criticism: Health Secretary Robert F. Kennedy Jr., a longtime vaccine sceptic, has promoted unproven remedies and overseen steep personnel and programme cuts at the CDC, contributing to what state officials describe as a climate of confusion and eroding trust in immunisation guidance.

A Pan-American Health Organization panel convenes in November to review whether the US has lost its measles elimination status. Canada lost its equivalent recognition last year. Regardless of the panel’s decision, the epidemiological data already signal a structural shift: a disease that kills tens of thousands annually in low-coverage settings worldwide is once again becoming persistent in American communities. The immediate milestone is the PAHO review; beyond that, the trajectory will depend on state-level vaccination drives and any federal recalibration of immunisation policy.