US measles cases have passed 5,000 in 2026, the highest annual total in 35 years, according to data released by the Centers for Disease Control and Prevention on Friday, 6 November. The agency counted 5,182 confirmed cases as of 5 November, more than double the 2,289 recorded in all of 2025.
The surge has spread across 47 jurisdictions, with 43 outbreaks reported this year and 96 percent of cases linked to outbreaks. Children have borne the brunt of the resurgence, and health officials warn the country’s measles-free status is now under review.
A four-year climb, laid out in the numbers
| Year | Confirmed cases | Outbreaks |
|---|---|---|
| 2026 (to 5 November) | 5,182 | 43 |
| 2025 | 2,289 | 48 |
| 2024 | 285 | 16 |
| 2023 | 59 | 4 |
The 2026 total is the highest the CDC has recorded since 1991. For comparison, the agency counted only 59 cases in 2023, before the count rose to 285 in 2024 and then jumped about eightfold last year.
Children account for most infections
Children under five account for 18 percent of this year’s cases, and children and teenagers aged five to 19 account for 41 percent, according to CDC data. Nearly all of the people infected were unvaccinated or had unknown vaccination status, a pattern the CDC has seen throughout the resurgence.
Measles spreads through the air when an infected person coughs or sneezes, and the virus can linger in a room after the person has left. Before the vaccine was introduced, an estimated 48,000 Americans were hospitalised and 400 to 500 died each year, the CDC says.
Why the death toll is disputed
The CDC’s count lists four deaths from measles in 2026, a figure the agency notes is subject to change as reviews are completed. State health authorities, however, have reported at least eight measles-related deaths, including among very young children, according to Al Jazeera’s reporting on the CDC data.
Pennsylvania accounts for much of the gap: the state’s health department has reported six deaths and 1,487 cases this year, counting any death within 30 days of symptom onset unless it was clearly unrelated. The CDC is working with state epidemiologists on a standard definition so deaths are classified the same way everywhere.
Vaccination coverage has slipped below the safety line
Routine childhood vaccination has fallen below the level needed to stop measles spreading. MMR coverage among kindergarteners dropped from 95.2 percent in the 2019–2020 school year to 92.4 percent in 2025–2026, leaving about 280,000 kindergartners at risk, the CDC says. Coverage above 95 percent is the threshold for community protection.
Two doses of the MMR vaccine are 97 percent effective at preventing measles, and one dose is 93 percent effective. Hospitals have been staffing up for the response, and health care added 42,000 jobs in October, including 16,000 in hospitals, according to the latest jobs report.
Elimination status now under review
Measles was declared eliminated in the United States in 2000, meaning the virus no longer spread on its own inside the country year-round. The Pan American Health Organization is due to review US transmission data on 10 November, and if it finds that one strain of the virus has circulated without a break for 12 months, the country could lose that status, Reuters reported.
The outbreak lands on the desk of a new Congress after the Democrats’ midterm sweep handed the party control of both chambers, with health policy and oversight of the administration’s response among the issues facing lawmakers when Congress returns on 9 November.
What health officials advise
The CDC calls the MMR vaccine the best protection against measles and urges people to check their vaccination records and talk to a health care provider, especially before travelling abroad. Most cases this year have been traced to unvaccinated people, and outbreaks have taken hold fastest in communities with lower coverage.
US measles outbreak 2026: your questions answered
How many measles cases has the US had in 2026? 5,182 confirmed cases as of 5 November 2026, according to the CDC — the highest annual total since 1991.
Is measles still eliminated in the United States? Formally yes, for now. Measles was declared eliminated in 2000, but the Pan American Health Organization is reviewing US data on 10 November and could revoke that status if one strain has circulated unbroken for 12 months.
How effective is the MMR vaccine? Two doses are 97 percent effective at preventing measles, and one dose is 93 percent effective, according to the CDC.
Why are measles cases rising? Cases are rising because vaccination coverage has fallen — kindergarten MMR coverage dropped to 92.4 percent — and the virus is finding pockets of unvaccinated people. Nearly all cases this year were in people who were unvaccinated or whose status was unknown.
