US measles outbreak worst in 35 years as 2026 case count surpasses 2025 total by July

A new peak after decades of decline

New figures from the US Centers for Disease Control and Prevention (CDC) released on Friday show 2,318 confirmed measles cases across the United States since the start of 2026. That single-year total, recorded with five months still remaining, already surpasses the 2,289 cases reported during all of 2025, a year that itself marked the highest figure in more than three decades and included three deaths, two of them young children. The last time the country recorded this many cases was 1991, when 9,643 infections were logged before a two-dose vaccination regimen drove numbers down sharply. Measles was declared eliminated in the United States in 2000.

“We are witnessing an avoidable crisis that disproportionally hurts children. We should not accept this as our new normal.”

Where the outbreaks are hitting hardest

Large outbreaks have been concentrated in South Carolina, Utah and Arizona, with additional clusters emerging in several other states. South Carolina alone has recorded 997 cases, a figure state health authorities acknowledge is likely an undercount. In total, 45 states have reported infections. Over the past month, Virginia and Pennsylvania have been dealing with new outbreaks, while Utah is still responding to a cluster that began in 2025. The true scope of the outbreak remains uncertain.

“I definitely believe that there is underdiagnosis. When you think about the people who are choosing not to vaccinate their children, these are also the people that have medical hesitancy in general.”

“What we're able to count and report is almost always an underestimate of what actually occurred, because it relies on people being willing to be able to get tested, to share information with healthcare providers and with public health. Sometimes that just doesn't happen.”

Erosion of vaccine coverage

National vaccination rates for kindergartners against diseases such as measles, mumps and rubella dropped to 92.5 percent during the 2024–2025 school year, below the 95 percent threshold that health authorities consider necessary to prevent outbreaks. In some communities the declines have been even steeper. Americans across much of the country can bypass school-entry vaccine mandates by citing religious or philosophical exemptions. The current outbreak has not been contained, and experts expect case numbers will continue to rise.

Political pressure and the Kennedy factor

US Health Secretary Robert F. Kennedy Jr has drawn sharp criticism from public health experts and organizations such as the American Academy of Pediatrics. Kennedy has a long history of downplaying the importance of immunizations and overstating their risks. While he has on occasion described the MMR vaccine as the "most effective way to prevent the spread of measles," he has also promoted unproven treatments and shared mixed messaging that experts argue has hindered outbreak response. Earlier this year, a federal judge blocked the US government from implementing sweeping changes to childhood vaccine policy.

“The whole world had their worst measles year.”

Looming loss of elimination status

International health officials are scheduled to meet in November to decide whether the United States and Mexico should lose their measles-free designation, a status Canada lost last year. A country forfeits elimination status when the same strain of measles virus circulates continuously for a year or more. The US has recorded more measles cases over the past 18 months than the total number logged in the 25 years prior. If the pattern holds, thousands of people each year could once again face a disease that before vaccination routinely sickened millions of children annually and killed hundreds in the United States alone.

19919,643

20252,289

2026 (partial)2,318

1991

9643 cases

2025

2289 cases

2026 (partial)

2318 cases

Data from the article text