Where The Measles Are Spreading in The U.S.

Where the Measles are Attacking and where it has a foot hold

The United States declared victory over measles 25 years ago. And yet one of the worst outbreaks since then is ravaging Texas and New Mexico.

For now, it isn’t a threat to most Americans. But there’s a reason this is happening — and why the next measles epidemic could be even worse.

In today’s newsletter, I’ll explain the virus’s possible resurgence in America.

Measles cases by county, 2025

A map shows (See above) measles cases by county in 2025 through March 13. Outbreaks have been identified in Texas, New Mexico and New Jersey. Isolated cases have been identified in Washington, California, Oklahoma, Kentucky, Georgia, Pennsylvania, New York, Vermont, Rhode Island, Maryland, Georgia, Florida and Alaska. 

Notes: Data is through March 13.Sources: State health departments; C.D.C.By The New York Times

Beating measles

Derailing this virus was a decades-long project. The United States began administering a vaccine in 1963, soon after its invention. At the time, the disease infected nearly all children before they turned 15. 

Why did containment take so long? Because measles is one of the most contagious viruses on the planet.

In a hypothetical community where nobody has immunity, each person with measles can infect up to 18 others. But this graphic by my colleague Jonathan Corum shows what happens when enough people are vaccinated:

A diagram shows how measles can spread across a community, and how vaccinations help slow or stop the spread of the virus. 

By Jonathan Corum

Experts generally want a community to have a vaccination rate of around 95 percent. That means, statistically, that the virus will spread to fewer than one person in the group, causing it to fizzle out.

That’s exactly what the United States accomplished in the early 2000s. A campaign to encourage inoculation, alongside strict vaccine requirements at public schools, dropped infections from nearly 28,000 in 1990 to just 85 a decade later. The cases that popped up here and there were mainly from international travel.

Yearly measles cases since 1985

 In 2025 so far, there have been more than 300 cases. 

Notes: Data is through March 13, 2024 and totals for 2023–2025 are preliminary.Source: C.D.C.By The New York Times

A reversal

Experts worry we may now revive the disease.

That’s because vaccination rates for the measles, mumps and rubella shot, which had been hovering around 95 percent, began to fall during the pandemic. Data from the last school year shows that only 93 percent of kindergartners were inoculated — the danger zone. In some regions of the country, such as West Texas, it’s closer to 80 percent. 

The country almost lost its elimination status from the World Health Organization thanks to an outbreak in New York six years ago. The fear now is that, as pockets of unvaccinated Americans continue to grow and multiply, measles will be more likely to hop from group to group, traveling farther and infecting more people. The current outbreak, which started in West Texas, has already spread to New Mexico and Oklahoma.

Why has the rate of vaccination fallen so much? Part of the answer lies in the Covid pandemic. Conspiracy theories about Covid-19 vaccines made many question the safety of other routine shots. The vaccine-skepticism movement is growing quickly, driven by declining trust in science and rampant misinformation on social media.

Unpopular pandemic mandates also fueled a revolt against vaccination requirements at public schools. In recent years, many states have weakened those mandates, which are perhaps the best way to keep childhood vaccination rates high. In 43 states, officials will grant an exemption based on religion. In 13 of those states, all you need is a personal objection to opt out of a school vaccine requirement.

Two futures

Some experts believe there is still time to rein in the virus. Perhaps if enough Americans witness the toll of measles, which killed an unvaccinated child in Texas in February, they will recall why vaccines are important. 

Others say that is naïve. They fear that distrust in science is so deeply rooted and that misinformation is so ubiquitous that many will choose to stay unvaccinated. And they worry that if vaccination rates don’t rise, other preventable diseases like polio will follow.

Vaccine skeptics now walk the corridors of power in Washington. President Trump has questioned the safety of vaccines. So has Robert F. Kennedy Jr., the nation’s top health official, who wrote a book about measles in 2021 saying that outbreaks had been fabricated so the government could “inflict unnecessary and risky vaccines on millions.” There is no cure for the virus, but Kennedy has also promoted unproven treatments: He said this month that doctors had told him about patients who had an “almost miraculous and instantaneous recovery” after they took cod liver oil, steroids and antibiotics. Health officials in Texas tell me such promises may have caused measles patients to delay medical care.

The outbreak in Texas supports the pessimistic thesis. There, even communities plagued by serious illness and death have still largely rejected the M.M.R. vaccine