Measles comeback: why the US could lose its elimination status in 2026
Measles has returned to countries that once eliminated it, driven by gaps in vaccination. The US has confirmed more than 5,000 cases in 2026, and regional health experts are reviewing its elimination status this week.
Measles is making a comeback because too few children in some communities are fully vaccinated. The United States had confirmed 5,182 cases in 2026 as of 5 November, more than double its 2025 total. This week, a regional expert commission is reviewing whether the US, which declared measles eliminated in 2000, has lost that status.
Why is measles coming back?
Measles returns when vaccination coverage falls below the level needed to stop it spreading. The World Health Organization says at least 95% coverage with two doses is needed to halt transmission. Globally, 84% of children received a first dose in 2024 and 76% a second, leaving more than 30 million children under-protected.
In the US, coverage among children starting school has slipped for several years. According to the Centers for Disease Control and Prevention (CDC), MMR coverage among kindergartners was 92.4% in the 2025-26 school year, and exemptions from one or more vaccines rose to 4.2% from 3.6%, about 155,000 children. Exemptions rose in 41 states and Washington DC, and 24 states reported rates above 5%.
Measles exploits even small gaps. The CDC says up to 9 in 10 unprotected people who come into close contact with an infected person will catch it, and the virus can infect people in a room up to two hours after the sick person has left.
How many measles cases are there in 2026?
The US is having its worst measles year in decades. The CDC's tracker recorded 5,182 confirmed cases as of 5 November 2026, with 43 new outbreaks and 96% of cases linked to outbreaks. The CDC lists four confirmed deaths, a figure it says is subject to change; some media tallies are higher.
Across the Americas, PAHO reported 57,666 confirmed cases in 17 countries and territories between January and October 2026, according to Al Jazeera. In Europe, the trend reversed after a peak: the WHO European Region reported 33,998 cases in 2025 in preliminary data, down about 75% from 127,412 in 2024, though still higher than in most years since 2000.
| Area | Period | Figure |
|---|---|---|
| United States | 2025 | 2,289 confirmed cases |
| United States | 2026, to 5 November | 5,182 confirmed cases |
| Americas | January–October 2026 | 57,666 confirmed cases |
| WHO European Region | 2025 (preliminary) | 33,998 cases |
| World | 2024 (estimate) | About 11 million cases, 95,000 deaths |
What does losing elimination status mean?
A country loses measles elimination status when the same strain of the virus spreads without interruption for 12 months or more. Under the rules of the Pan American Health Organization (PAHO), this counts as re-established endemic transmission. For the US, the analysis period starts with the outbreak that began on 20 January 2025; for Mexico, on 1 February 2025.
Canada was the first to fall. In November 2025, PAHO's regional verification commission concluded that endemic transmission had been re-established there, which also meant the Americas as a whole lost its status as free of endemic measles. The commission is meeting from 10 to 13 November 2026 to review the US, Mexico and other countries, and PAHO's director will make the final decision. As of 12 November 2026, no decision on the US had been announced.
Losing the status does not change how outbreaks are handled day to day. It is a formal recognition that the disease is circulating locally again rather than only arriving through travel. Brazil lost its status in 2019 and regained it in 2024 after a vaccination campaign.
How dangerous is measles?
Measles can be serious, especially for children under five. Common complications include ear infections and diarrhoea; serious ones include pneumonia and encephalitis, a swelling of the brain, and the disease can kill. The WHO estimated about 95,000 measles deaths worldwide in 2024, mostly among young children, even after an 88% fall in deaths since 2000.
How well does the vaccine protect?
The MMR vaccine is highly effective. The CDC says one dose is 93% effective against measles and two doses are 97% effective. The WHO credits measles vaccination with saving nearly 59 million lives since 2000. National schedules differ on timing, so families should follow local advice.
Travel is a common way measles crosses borders. Anyone planning a trip, for example to Europe under the new EU entry and exit rules or to crowded destinations described in our piece on overtourism in European cities, can check their vaccination records before leaving.
Frequently asked questions
Has the US lost its measles elimination status?
Not as of 12 November 2026. PAHO's regional verification commission is meeting from 10 to 13 November to review the evidence, and PAHO's director will make the final decision. The US declared measles eliminated in 2000 and has had sustained outbreaks since January 2025, so several experts expect the status to be lost.
Why did Canada lose its measles elimination status?
In November 2025, PAHO's regional commission concluded that the measles virus had circulated in Canada without interruption for at least 12 months. That meets the definition of re-established endemic transmission. Because Canada is part of the region, the Americas as a whole also lost its status as free of endemic measles.
Are adults protected against measles?
Most adults who had two doses of MMR, or who had measles, are protected. The CDC says two doses are 97% effective. Adults unsure of their vaccination history can ask a doctor, who may recommend a dose. The CDC advises adults to have at least one documented dose, and two for some higher-risk groups.
How many measles cases were there in Europe in 2025?
Preliminary WHO and UNICEF data show 33,998 cases in the WHO European Region in 2025, down about 75% from 127,412 in 2024. The agencies warned that the final total may be higher and that 19 countries had continuing or re-established endemic transmission, up from 12.
What vaccination rate stops measles spreading?
The WHO says at least 95% of people need two doses of a measles vaccine to stop transmission, and that level is needed in every community, not just nationally. In 2024, global coverage was 84% for the first dose and 76% for the second, well short of that target.
Sources
- CDC — Measles cases and outbreaks (updated 6 November 2026)
- CDC — Vaccination coverage and exemptions among kindergartners (2025-26 school year)
- PAHO/WHO — Update on the review of measles elimination status (2 March 2026)
- PAHO/WHO — Measles deaths down 88% since 2000, but cases surge (28 November 2025)
- UNICEF and WHO Europe — Measles cases dropped in Europe and Central Asia in 2025 (11 February 2026)
- Al Jazeera — Why the US, Mexico and Guatemala may lose their measles-free status (12 November 2026)
- CDC — Measles vaccines
- CDC — About measles
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