Why measles cases have hit a 33-year high in the US

The United States is facing its most severe measles outbreak in over three decades, with 1,277 confirmed infections recorded so far this year across 38 states and Washington, DC, according to data compiled by Johns Hopkins University’s Center for Outbreak Response Innovation (CORI).

This marks the largest annual tally of cases since 1992, when more than 2,100 infections were reported nationwide.

By surpassing the 1,274 cases of 2019, the current outbreak has alarmed public health authorities, particularly because three measles-related deaths — two in Texas and one in New Mexico — have already been reported this year.

According to the Centers for Disease Control and Prevention (CDC), all three individuals were unvaccinated and had no underlying medical conditions.

In addition to the fatalities, 155 individuals have been hospitalised due to complications.

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The CDC noted that approximately 92 per cent of this year’s measles cases involved individuals who either had not received the MMR (measles, mumps, rubella) vaccine or whose vaccination status could not be confirmed.

Where is the outbreak epicentre in the US?

The Southwest region, especially West Texas, has been identified as the primary hotbed of infections.

In Gaines County, a largely Mennonite population — some of whom homeschool or send their children to private schools that do not enforce vaccination requirements — has been significantly affected.

With an MMR immunisation rate of just 82 per cent among kindergartners in the county, state health officials said the virus spread rapidly after initial cases were identified in late January.

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The virus’s transmission continued to grow despite the slowdown in recent weeks. At least 750 cases have been reported in Texas, and 36 counties in the state have now confirmed infections.

Health officials suspect the actual number could be much higher due to underreporting and lack of testing.

From Texas, the outbreak extended into neighbouring areas. Kansas and New Mexico have both reported dozens of infections, and additional spread has reached Oklahoma, Arkansas, Illinois, Indiana, Michigan, and Ohio.

More recently, Colorado, Montana, and North Dakota have also seen new cases. In El Paso, young workers in oil fields connected to Gaines County have contributed to the virus’s transmission chain.

The virus even crossed international borders. In Chihuahua, Mexico, a child who travelled to Texas in February is believed to have sparked a large outbreak now exceeding 2,400 confirmed cases and eight fatalities, according to the Pan American Health Organization.

Is it because of vaccine scepticism in public?

Once considered a triumph of American public health policy, measles was declared eliminated in the United States in 2000, following years of high immunisation coverage and swift containment measures. However, recent years have seen growing scepticism toward vaccines, leading to the re-emergence of preventable diseases.

Experts attribute much of the current crisis to falling MMR vaccination rates, with CDC data showing national coverage among kindergartners dropping from over 95 percent in 2019 to below 93 percent in 2025.

That shift is attributed in part to disinformation about vaccines, a factor that also fueled the 2019 outbreaks in tight-knit religious communities in New York.

Even in areas with generally high vaccination levels, unvaccinated individuals tend to form pockets, allowing the virus to gain a foothold.

Since measles is one of the most contagious viruses in the world, exposure typically leads to infection in 90 per cent of non-immune individuals, often before symptoms manifest.

The Covid-19 pandemic exacerbated mistrust in federal health institutions. According to a KFF poll from April, fewer than 50 per cent of Americans say they retain confidence in federal public health agencies.

Meanwhile, a March survey from the Harvard TH Chan School of Public Health and the de Beaumont Foundation found that 79 per cent of adults support mandatory vaccinations for children attending school.

That number, however, breaks down sharply along political lines: 90 per cent of Democrats support school vaccination mandates, compared to 68 per cent of Republicans.

What is RFK Jr doing about the situation?

US Health and Human Services Secretary Robert F Kennedy Jr has long been one of the country’s most prominent vaccine sceptics. His appointment to the top health post came as a shock to many public health officials and has become even more controversial during the ongoing measles outbreak.

Initially, Kennedy appeared to minimise the scale of the crisis, stating, “We have measles outbreaks every year.”

He later clarified his stance in a post on X, writing that the MMR vaccine is “the most effective way to prevent the spread of measles.”

However, Kennedy’s public messaging continues to include caveats and doubts about vaccine safety, which epidemiologists have labelled baseless and potentially harmful.

In response to the growing crisis, HHS spokesperson Andrew Nixon stated: “[Kennedy] has responded to the measles outbreak with clear guidance that vaccines are the most effective way to prevent measles. At the same time, we recognise that some individuals and communities across the U.S. may choose not to vaccinate.”

Nixon also noted that the CDC has rolled out a measles tool kit to help local communities manage the crisis with options tailored to specific populations.

Complicating matters, Kennedy visited Gaines County during the height of the Texas outbreak and publicly praised an anti-vaccine doctor who had offered unproven alternative treatments to affected families, reported The Washington Post.

Many Mennonite parents turned to this physician instead of following CDC guidance.

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Kennedy’s anti-vaccine organisation, Children’s Health Defense, also entered the fray, publishing interviews with the parents of a 6-year-old girl who died of measles, attributing her death to alleged medical error rather than lack of vaccination.

What’s next?

The measles resurgence is not limited to the United States. In England, 2024 saw nearly 3,000 confirmed infections, the highest number since 2012.

Canada has also reported over 3,000 cases so far in 2025, mainly concentrated in the provinces of Ontario and Alberta.

These figures reflect a broader global trend, as misinformation, pandemic-driven distrust and delayed childhood vaccinations have created fertile ground for outbreaks.

In the US, without urgent intervention, researchers estimate that millions of measles infections could occur over the next 25 years if current vaccination patterns continue.

With inputs from agencies