The United States officially passed 1,000 cases of measles in 2026

The United States just passed a grim milestone with measles

By Lauren J. Young edited by Claire Cameron

The United States has officially passed 1,000 cases of measles in 2026. The Centers for Disease Control and Prevention’s latest disease count reveals that as of February 26, 1,136 people have confirmed measles infections. What that means is that in just two months, the national total is already approaching half of all 2,281 confirmed cases reported in 2025.

Measles is a vaccine-preventable viral disease that is both extremely contagious and potentially fatal. The United States was declared free of measles in 2000, but experts say that achievement is almost certain to be reversed. The infection rate this year is accelerating at a much faster pace than even during the outbreak that began in West Texas in 2025. The spike has alarmed public health experts, many of whom blame the disease’s resurgence on declining measles vaccination rates.

“Hitting 1,000 (cases) in February is unprecedented, but it’s not because there’s anything new about the virus or the disease like when there are new strains of flu. It’s unprecedented because of how preventable it is,” said Amy Winter, a demographer and epidemiologist at the University of Georgia’s College of Public Health. “This is 100 percent a reflection of recent declines in vaccination rates.”

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The CDC’s numbers are likely an undercount, and there are likely many more cases in the United States that are going undetected or unreported. Most of the confirmed cases — 90 percent — are linked to increases in more than a dozen states, with a relentless outbreak in South Carolina fueling most of the infections this year. As of February 27, South Carolina’s Department of Public Health reported a total of 985 cases since the fall of 2025; 919 of these cases were in people who did not receive the measles, mumps and rubella (MMR) vaccine.

Last year, 11 per cent of people who contracted measles were admitted to hospital. The disease can cause an itchy rash, fever, severe encephalitis and death. Two children and an adult died of infection last year – all three people were unvaccinated.

“When you’re vaccinated, it not only helps your own family or child, but it also helps your community,” says Walter Orenstein, an epidemiologist and professor emeritus at Emory University School of Medicine.

The MMR vaccine is highly protective against measles – the shot gives people up to 97 percent protection for life after they receive the two recommended doses. But because measles is so contagious, communities need high levels of herd immunity—meaning at least 95 percent of the population needs immunity from vaccination or previous infection to prevent the disease from spreading. Especially babies younger than 12 months and people who are immunocompromised or have a medical condition that prevents them from getting the vaccine benefit from high herd immunity, explains Orenstein.

“A failure to vaccinate not only puts these children or individuals at risk, but also puts society at risk, including people who have legitimate medical conditions and cannot be vaccinated,” he says. “With declining immunity, we are at real risk of measles becoming endemic again (in the United States) and infecting more people and potentially even killing more people.”

Since elimination was achieved in 2000, a number of measles cases have typically appeared in the United States each year, usually as a result of people becoming infected through exposure abroad. But since 2025, the relatively limited amount of cases is no longer. What is happening now is evidence of greater local transmission in the country, says Winter. If a chain of localized infection persists for more than 12 months, the United States will lose its measles-free status. The Pan American Health Organization will review the United States’ measles elimination status in April.

“In my mind, we’ve already lost elimination status,” Winter says.

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