US Measles Outbreak Reaches Highest Level in 35 Years – Children Disproportionately Affected

William Moss, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, expressed concern about the development. "That we are reaching this milestone is particularly glaring, given that it is only July and measles cases continue to be reported nationwide," he said. The previous record stems from the period between 1989 and 1991, when the United States experienced large-scale measles waves over several years.

The cases now span 45 US states as well as the District of Columbia. Particularly affected, alongside South Carolina – where a single outbreak since October 2025 has sickened nearly 1,000 people over six months – are Utah, Arizona, Texas, Florida, Virginia, and Pennsylvania. South Carolina is thus recording the largest local outbreak since the turn of the millennium.

South Carolina: Largest Local Outbreak Since the Turn of the Millennium

The CDC has registered 35 new measles outbreaks so far this year, after there had been 48 outbreaks in the entire previous year. Sixteen of the cases recorded this year are linked to travelers from abroad, according to the agency. A total of 151 people required hospital treatment for a measles infection.

Particularly alarming is the age distribution of the illnesses. Sixty-nine percent of those infected are children and adolescents up to age 19, and one-fifth of those affected are younger than five years. Ten percent of sick toddlers under five were treated in hospital, while the hospitalization rate for older children and adolescents was three percent.

Children Disproportionately Affected

Experts see a direct connection with falling vaccination rates. The average MMR vaccination rate – which protects against measles, mumps, and rubella – fell to 92.5 percent among children of school-entry age last year. This places it below the herd immunity threshold of 95 percent applicable to measles. In 16 states, the vaccination rate among kindergarten children is even below 90 percent.

Vaccination Rate Below Herd Immunity Threshold

"We are experiencing a preventable crisis that is disproportionately affecting children," said Andrew Racine, president of the American Academy of Pediatrics. He pointed out that 93 percent of those sickened had been unvaccinated, while the remaining share had received one or two doses of the vaccine. A complete vaccination with two doses provides 97 percent protection, according to the CDC.

Criticism of Political Communication

Racine sharply criticized the political level. "Since the beginning of last year, leading federal politicians have dismissed measles as harmless and inevitable and spread misleading information about the MMR vaccine," he said. A central figure in this criticism is US Health Secretary Robert F. Kennedy Jr., who has repeatedly spread the scientifically disproven claim that measles vaccinations are linked to autism.

In June of the previous year, Kennedy had dismissed all members of the CDC's expert vaccine panel. Since then, professional organizations have warned of growing uncertainty among the population. The American Academy of Pediatrics is among the medical societies publicly advocating for a broad vaccination campaign.

Despite the high case numbers, no deaths from measles have been reported so far this year. In the previous year, three people died as a result of measles infection. Measles can cause fever, rash, and respiratory problems, according to the CDC; in severe cases, complications such as pneumonia or life-threatening encephalitis can occur.

Status of the 2000 Measles Elimination Declaration

The United States officially declared measles eliminated in the year 2000. This designation meant that there was no longer a permanent domestic transmission chain of the virus. With the current outbreaks, this label is increasingly in question, although the CDC has so far not formally withdrawn the declaration.

Reporting on the situation was picked up by, among others, Reuters and broadcast on July 25, 2026 via Deutschlandfunk. The Austrian news agency APA distributed the report on the same day. The development is thus receiving increasing attention in European reporting as well, as Europe has likewise faced rising measles numbers in recent years.

Health experts emphasize that individual vaccine doses are not sufficient to stop the spread of the virus. Only a vaccination rate well above 95 percent in the population provides so-called herd immunity, which also protects those people who cannot be vaccinated for medical reasons – including infants, pregnant women, or immunocompromised individuals.

With the upcoming school year in mind, pediatricians are calling for the vaccination status of children and adolescents to be checked. The American Academy of Pediatrics recommends the first MMR dose between the ages of 12 and 15 months and the second dose between four and six years. Catch-up vaccinations are possible at any time, physicians emphasize.