The United States has recorded 5,182 confirmed cases of measles so far in 2026, the highest annual total in 35 years, according to data released by the Centers for Disease Control and Prevention (CDC) on Friday. The figure, counted through 5 November, is more than double the 2,289 cases reported in all of 2025 and the highest the CDC has recorded since 1991.
The weekly update added 330 cases in a single week. The outbreak has now reached 45 states plus Washington, D.C. — and the milestone arrives as a dispute over how measles deaths are counted has left the federal tally well below the number reported by state health officials.
The numbers behind the milestone
Measles is a highly contagious but vaccine-preventable disease, and the CDC's latest figures show how far the outbreak has spread this year. According to the CDC, 96 percent of confirmed cases — 4,993 of 5,182 — are linked to outbreaks, and 43 outbreaks have been reported so far in 2026.
| Measure | 2026 figure | Comparison |
|---|---|---|
| Confirmed cases | 5,182 (as of 5 November) | 2,289 in all of 2025 |
| Weekly increase | 330 cases | Up 6.8% on the previous update |
| Hospitalisations | 562 (11% of cases) | — |
| Outbreaks reported | 43 | 96% of cases outbreak-associated |
| Cases unvaccinated or status unknown | 96% | — |
| Deaths (CDC count) | 4 | 3 in all of 2025 |
| Deaths (state officials' count) | At least 8 | — |
Children and teenagers make up almost 60 percent of confirmed cases, according to the CDC's breakdown: 908 cases are in children under five, 2,104 in children and teenagers aged five to 19, and 2,132 in adults aged 20 and over. Hospitalisations linked to measles this year stand at 562, representing 11 percent of all reported cases.
More than double last year's total — and 96 percent of cases are among people who were unvaccinated or whose vaccination status is unknown.
Where the outbreak is concentrated
Pennsylvania is the hardest-hit state, with 1,487 cases and 287 hospitalisations reported by its health department, according to Reuters. South Carolina and Utah recorded the next-highest counts, at 670 and 536 cases respectively.
Three states reported measles-associated deaths in a single week between 2 and 5 November. Pennsylvania reported its sixth death of 2026 on 4 November, involving an unvaccinated Jefferson County resident who tested positive for measles. Wisconsin reported the death of an infant on 5 November — the state's first measles death since 1990 — and New York reported the death of a child in Lewis County, its first in more than 30 years.
A dispute over the death toll
The number of deaths is where the official picture splits. According to CDC data, four people have died of measles in 2026, compared with three deaths in all of 2025. But state health officials have reported at least eight measles-related deaths this year, including among very young children.
The two counts differ because the CDC and the states are no longer counting deaths the same way. Pennsylvania reports a "measles-associated" death when a person with confirmed measles dies within 30 days of developing symptoms, unless the death resulted from an unrelated event. The CDC, under Health Secretary Robert F. Kennedy Jr., switched to using National Center for Health Statistics mortality data to track measles deaths — and in August it removed two Pennsylvania deaths from its national tally after Kennedy questioned whether measles had caused or contributed to them. The CDC has said it is working with the US Council of State and Territorial Epidemiologists to establish a standardised definition for measles deaths.
The dispute has drawn in Pennsylvania Governor Josh Shapiro, who has publicly challenged the federal approach, and infectious disease experts have warned that the change puts the CDC at odds with a longstanding approach to tracking the consequences of measles. Epidemiologists told Al Jazeera that tracking "measles-associated" deaths has long been a standard used by the World Health Organization and the CDC.
Why cases are rising
The resurgence tracks a long slide in vaccination coverage. Vaccination coverage among US kindergarteners has fallen from 95.2 percent in the 2019–2020 school year to 92.4 percent in 2025–2026, according to Al Jazeera — below the roughly 95 percent coverage level generally needed to stop measles spreading in a community.
Measles cases have also risen globally, particularly in communities that are vaccine-sceptical or where there are gaps in healthcare access. The United States declared the virus eliminated in 2000, meaning it was no longer spreading continuously within the country — but elimination depends on high vaccination coverage, and imported cases can seed outbreaks wherever immunity has thinned.
Measles is one of the most contagious diseases known, and the virus can linger in the air for up to two hours after an infected person leaves a room. The MMR vaccine — two doses of measles, mumps and rubella vaccine — is about 97 percent effective at preventing measles, according to the CDC.
What happens next
The World Health Organization is expected to review the US measles elimination status on 10 November, following the 2025 Texas outbreak that killed three people. If the review finds that measles is again spreading continuously, the US could lose the elimination status it has held since 2000.
The CDC will publish its next weekly update on Friday, and health officials will be watching whether the weekly increase stays above 300 cases — a pace that would push the annual total higher still before the year ends.
Frequently asked questions
How many measles cases has the US had in 2026?
The CDC reported 5,182 confirmed cases as of 5 November 2026 — the highest annual total since 1991 and more than double the 2,289 cases recorded in all of 2025.
How many people have died of measles in the US this year?
It depends on whose count is used. The CDC's official tally is four deaths in 2026; state health officials have reported at least eight, including six in Pennsylvania, an infant in Wisconsin and a child in New York. The gap comes from a change in how the CDC classifies measles deaths.
Who is most at risk?
Children and teenagers account for about 59 percent of confirmed cases, and 96 percent of all cases are among people who were unvaccinated or whose vaccination status is unknown. Infants too young to be vaccinated and people with weakened immune systems are among the most vulnerable.
Does the MMR vaccine protect against measles?
Yes. Two doses of the MMR vaccine are about 97 percent effective at preventing measles, according to the CDC, and the vaccine has been used safely for decades.
Could the US lose its measles elimination status?
Possibly. The World Health Organization is expected to review the US elimination status on 10 November. Elimination means measles is not spreading continuously within the country; sustained transmission over a year can cost a country that status.
Key takeaways
- The CDC reported 5,182 confirmed measles cases in the US in 2026, the highest annual total since 1991 — more than double the 2,289 cases of 2025.
- Hospitalisations stand at 562, or 11 percent of cases, and 43 outbreaks have been reported, accounting for 96 percent of infections.
- Children and teenagers make up about 59 percent of cases; 96 percent of cases are among the unvaccinated or those with unknown vaccination status.
- The death toll is disputed: the CDC counts four deaths, while state officials report at least eight — a gap caused by a change in how the CDC classifies measles deaths.
- The WHO is expected to review the US measles elimination status on 10 November.
The milestone is a warning as much as a statistic. Measles was declared eliminated in the US in 2000; keeping it that way depends on vaccination coverage that has now slipped below the threshold needed to stop the virus spreading. The next CDC update, the WHO review on 10 November, and the weekly case counts through the winter will show whether the outbreak is still accelerating — or whether the response is catching up.
