The United States faces a surge in measles cases, putting its measles-free status at risk. The outbreak highlights similar vulnerabilities in European communities where vaccination coverage is too low to stop the disease from spreading.
More than 4,500 cases have been reported in the US this year. This is roughly double the total from last year. A forecast in JAMA warns measles could become endemic in the US if vaccination rates do not improve. The model projects 851,300 cases over 25 years, leading to more than 170,000 hospitalizations and 2,550 deaths.
The outbreak in the US also signals a wider global risk. “Due to international travel routes and the ease and speed at which people move across borders, combined with the infectiousness of measles before the rash starts, people can travel quite far whilst infectious and so the disease can spread rapidly,” said Kitty Mohan, vice-president of the Standing Committee of European Doctors (CPME).
Measles is one of the most contagious infectious diseases. People can transmit the virus for about four days before the characteristic rash appears. This means they may cross borders before realizing they are ill. “15 mins face to face with someone who is infectious will mean you are likely to get measles,” Mohan said.
The US is not alone in dealing with ongoing measles circulation. The largest current outbreaks are in Bangladesh, with over 65,430 cases, Indonesia with 46,578, and Guatemala with 31,222 cases.
“Whether an imported case leads to further transmission in Europe depends primarily on immunity levels in the affected community in Europe and whether the virus reaches groups with low vaccination coverage,” stated the European Centre for Disease Prevention and Control (ECDC).
ECDC data shows vaccination coverage in Europe was 92% for the first dose and 88% for the second dose. While this is described as “strong population protection,” it remains below the recommended 95% two-dose coverage needed to prevent sustained transmission. National averages can hide areas with much lower vaccination rates.
“There are traditional risk groups – such as traveller communities and some religious groups who historically have been reluctant to vaccinate,” said Mohan. However, the ECDC pointed out that a cluster of unvaccinated people does not automatically lead to a wider outbreak. The Urkult festival in northern Sweden serves as an example. An outbreak there this summer involved 28 cases but did not spread further due to high population immunity.
For Europeans, the risk level is currently moderate for infants under 12 months, children aged one to five, and immunocompromised people. For older unvaccinated children and adults, the risk is low to moderate. People with immunity from vaccination or past infection are considered at low risk.
ECDC surveillance data show fewer measles cases reported so far in 2026 than in 2025, though 2026 figures are preliminary. Measles is endemic in twelve European countries, including Bosnia and Herzegovina, France, Germany, and Italy. Romania reported the most cases in 2024, with 30,692, a sharp increase from the previous year.
