Measles resurgence in the United States

Based on Wikipedia: Measles resurgence in the United States

In the year 2000, the World Health Organization made an announcement that would have seemed like science fiction just a generation earlier: measles had been eliminated from the United States. The disease that once infected three to four million Americans annually, hospitalizing 48,000 and killing up to 500 each year, had been vanquished through one of public health's greatest triumphs—mass vaccination.

That victory is now unraveling.

The Most Contagious Disease You've Never Worried About

To understand why health officials speak of measles with such urgency, you need to grasp just how extraordinarily contagious this virus is. If you're unvaccinated and walk into a room where someone with measles coughed two hours ago, you have a 95 percent chance of catching it. The virus hangs in the air, waiting.

Epidemiologists measure a disease's contagiousness using something called the basic reproduction number, often written as R₀ (pronounced "R-naught"). This number represents how many people, on average, a single infected person will spread the disease to in a population with no immunity. For seasonal flu, that number hovers around 1.3. For the original strain of COVID-19, it was between 2 and 3.

For measles? It's 12 to 18.

This means in an unvaccinated population, every person who catches measles spreads it to more than a dozen others. The virus is so efficient at transmission that it requires an immunization rate of about 95 percent to achieve what's called herd immunity—the point at which enough people are protected that the virus can't find easy paths through a community.

The Elimination That Wasn't Permanent

When epidemiologists declared measles "eliminated" from the United States, they didn't mean the virus had vanished from Earth. Measles remained endemic in many countries, circulating freely through populations. What elimination meant was simpler: any new cases in America would be imported from abroad, not generated through sustained domestic transmission.

For years, this arrangement held. International travelers occasionally brought the virus home, but high vaccination rates meant these sparks couldn't ignite larger fires. The system worked exactly as designed.

Then the sparks started finding fuel.

How Doubt Became Disease

The story of measles' return is inseparable from the story of vaccine hesitancy—a polite term for what happens when enough parents become convinced that vaccines pose greater risks than the diseases they prevent.

The measles-mumps-rubella vaccine, commonly called the MMR, became the focus of particular suspicion after a 1998 paper by British researcher Andrew Wakefield claimed to find a link between the vaccine and autism. The paper was later revealed to be fraudulent. Wakefield had manipulated data, and he had undisclosed financial conflicts of interest. The journal retracted the study. Wakefield lost his medical license.

But the damage was done. The idea had entered the cultural bloodstream, and it proved nearly as contagious as the virus itself.

The director of the National Institutes of Health wrote in 2016 that parents refusing to vaccinate their children were leading directly to outbreaks of preventable diseases. The World Health Organization identified anti-vaccination movements as a direct cause of rising measles cases globally.

The Geography of Vulnerability

Vaccine hesitancy doesn't distribute itself evenly across the American landscape. It clusters. It concentrates in particular communities, creating pockets of vulnerability where the virus can establish footholds.

Consider California. Statewide, 97 percent of kindergarteners are vaccinated—comfortably above the threshold for herd immunity. But state averages mask dangerous local realities. At the Santa Cruz Waldorf School in 2018, only 33 percent of students were vaccinated. At Berkeley Rose School in Alameda County in 2014, the rate was 13 percent—roughly one in seven children.

These aren't random numbers. Waldorf schools, founded on the educational philosophy of Rudolf Steiner, have historically attracted parents skeptical of conventional medicine. The schools themselves don't oppose vaccination, but the communities that form around them often include significant numbers of vaccine-hesitant families.

California eventually responded. In 2016, the state eliminated "philosophical objections" as a valid reason to skip childhood vaccinations. Only medical exemptions remained. The effect was immediate: Berkeley Rose School's vaccination rate climbed from 13 percent to 57 percent.

Still not enough for herd immunity. But progress.

The Happiest Place on Earth Becomes Ground Zero

In late December 2014, someone carrying the measles virus visited Disneyland in Anaheim, California. The theme park, with its tightly packed crowds and long lines, proved an ideal transmission environment. Within weeks, 131 California residents had been infected, along with people in six other states, plus Canada and Mexico.

The Disneyland outbreak became a turning point. It was visible, frightening, and impossible to ignore. Healthy children were getting seriously ill because other parents had chosen not to vaccinate. The outbreak gave California the political momentum to pass its strict new vaccination law.

But other states took different lessons from the same events.

The Orthodox Jewish Communities and 2019's Record Year

By April 2019, the United States had recorded 764 measles cases—the highest number in 25 years. Most of the infected were unvaccinated. More than 500 had never received the vaccine at all; another 125 had unknown vaccination status.

The bulk of these cases came from Orthodox Jewish communities in and around New York City, particularly in the Brooklyn neighborhoods of Williamsburg and Borough Park, and in suburban Rockland County.

It's important to understand why. Jewish law does not prohibit vaccination. Major rabbinical authorities have consistently ruled that vaccines are permitted and even required under the Jewish obligation to preserve health. But some Orthodox communities have low vaccination rates for cultural rather than strictly religious reasons—tight-knit social networks can amplify minority viewpoints, including vaccine skepticism.

The outbreak appears to have started when an unvaccinated child traveled to Israel, where a large outbreak was already underway, and returned to Brooklyn carrying the virus. From there, it spread through schools, synagogues, and the dense web of social connections that characterizes Orthodox life.

Between October 2018 and April 2019, New York City confirmed 423 cases. Mayor Bill de Blasio declared a state of emergency and ordered mandatory vaccinations in four ZIP codes. Residents who refused faced fines of $1,000. Schools and day care centers that admitted unvaccinated students were shut down.

In Rockland County, the situation grew severe enough that officials banned unvaccinated children from all public places for 30 days. Parents who violated the order risked six months in jail. A judge eventually lifted the ban, ruling that the outbreak didn't qualify as an emergency under existing law, but the episode revealed just how seriously officials were taking the threat.

When Measles Flies

In March 2019, a flight attendant worked a route from New York City to Tel Aviv. Days later, passengers received alarming notifications: the woman had developed measles encephalitis—inflammation of the brain caused by the measles virus. She was in the intensive care unit on a ventilator.

Measles encephalitis affects roughly one in every thousand people who contract the disease. About one in four of those who develop it will die; many survivors suffer permanent brain damage. The flight attendant's case illustrated something easy to forget in discussions about vaccination rates and herd immunity: behind the statistics are individual human tragedies.

On average, in the United States, two or three of every thousand children who catch measles will die. One in a thousand will develop brain complications that often cause permanent damage. These odds might sound small until you remember that before the vaccine, three to four million Americans caught measles every year.

Clark County and the "Anti-Vaccination Hotspot"

The areas surrounding Vancouver, Washington—particularly Clark County—earned a grim distinction in late 2018 and early 2019: journalists labeled the region an "anti-vaccination hotspot." The local vaccination rate had fallen to 78 percent, well below the 95 percent threshold needed for herd immunity against measles.

By April 2019, health officials had confirmed 74 cases. More than half of those infected were children under ten. Seventy had never been vaccinated or had unknown vaccination status. The outbreak spilled across the Columbia River into Oregon.

Washington State Representative Paul Harris responded by proposing legislation to eliminate philosophical exemptions for required childhood vaccines. The bill was amended to focus specifically on the MMR vaccine. Under the new law, children couldn't attend public or private schools or day care without proof of vaccination or an approved medical exemption.

The bill passed in April 2019—but only after measles had already sickened dozens of children.

A President Changes His Mind

Donald Trump had previously expressed skepticism about vaccines, advocating for "spacing out" the standard vaccination schedule. The 2019 outbreak changed his public position.

"They have to get the shots," Trump said. "The vaccinations are so important."

His Surgeon General, Jerome Adams, drew explicit connections between states with generous vaccine exemptions and higher outbreak risks. Adams advised health officials on strategies to encourage vaccination.

It seemed, for a moment, like a bipartisan consensus might be forming around the necessity of childhood immunization.

The 2024 Florida Outbreak and a Different Approach

In February 2024, measles appeared at Manatee Bay Elementary School in Broward County, Florida. What happened next marked a departure from standard public health practice.

Florida's Surgeon General, Joseph Ladapo, acknowledged that the "normal" recommendation was for unvaccinated children exposed to measles to stay home. The Centers for Disease Control and Prevention recommends a 21-day quarantine for anyone without immunity who has been exposed.

But Ladapo took a different approach. He wrote to parents that his department was "deferring to parents or guardians to make decisions about school attendance." In other words: even if your unvaccinated child had been directly exposed to one of the most contagious diseases on Earth, the state of Florida wouldn't require them to stay home.

Public health experts were alarmed. Epidemiologist Katelyn Jetelina and physician Kristen Panthagani called Ladapo's advice "unprecedented and dangerous." Leana Wen, a former Baltimore health commissioner, described the decision as "outrageous."

The Broward outbreak was declared over on March 7, 2024. Whether Florida's approach shortened or lengthened it, or whether it was simply luck that prevented wider spread, remains debated.

Chicago's Shelter Outbreak

In March 2024, Chicago confirmed its first measles cases since 2019. Both were detected in a migrant shelter in the Pilsen neighborhood.

The outbreak grew quickly. By March 10, more cases had been reported. The Centers for Disease Control and Prevention dispatched a team to assist. By March 14, cases had appeared in two Chicago public schools, bringing the city's total to ten. On March 15, Chicago announced it would require migrants at city shelters to receive the MMR vaccine.

The shelter outbreak illustrated how measles exploits vulnerability. Migrants in shelters often come from countries with lower vaccination rates or disrupted health systems. They live in close quarters. They may lack access to medical care. The virus doesn't discriminate based on immigration status, but the conditions that allow it to spread often correlate with poverty and displacement.

West Texas, 2025: The Worst Outbreak in Three Decades

In late January 2025, measles cases began appearing in the South Plains region of West Texas, centered around Gaines County. By mid-February, the outbreak had grown to 48 confirmed cases. Health officials suspected the true number might be much higher—perhaps 200 to 300 infected but untested.

The timing was notable. The outbreak began shortly after Donald Trump's inauguration for his second presidential term and the appointment of Robert F. Kennedy Jr. as Secretary of Health and Human Services. Kennedy, who has spent years promoting vaccine misinformation, initially downplayed the outbreak, describing it as "not unusual."

The data suggested otherwise. This was the worst measles outbreak Texas had seen in nearly 30 years. About 27 percent of cases required hospitalization—an unusually high rate that reflected both the severity of the disease and perhaps delays in seeking treatment.

By late February, the outbreak had crossed state lines into New Mexico. Total confirmed cases reached 133. And then came the deaths.

On February 26, 2025, officials confirmed that two unvaccinated patients had died: one child in Texas, one adult in New Mexico. The child's death was the first measles fatality in the United States since 2015.

The affected area included a large Mennonite community. Mennonites, like the Amish, often have low vaccination rates due to religious beliefs and cultural separation from mainstream society. Texas and New Mexico have high overall vaccination rates—94.3 percent and 95 percent among kindergarteners, respectively—but exemptions have been rising, and the communities with low rates created exactly the conditions measles needs to spread.

The Numbers Keep Climbing

By April 2025, the West Texas outbreak had grown to 624 cases and two child deaths. New Mexico reported 65 cases. Oklahoma had 13. Kansas had 37. Outbreaks were also reported in Indiana and Ohio.

By late May, Texas confirmed 729 total cases statewide. Gaines County alone accounted for 408. New Mexico reached 79 cases, Kansas 64, Oklahoma 17.

In Michigan, Marquette County confirmed a single case—a reminder that measles can appear anywhere, sparked by a single traveler.

Iowa, which hadn't seen a measles case since 2019, reported six in May and June 2025. State health officials revealed that Iowa's vaccination rate for two-year-olds had fallen to 84 percent for the first dose of MMR—well below the threshold for herd immunity.

Looking Forward: A Grim Projection

In April 2025, researchers published a study with a sobering projection: over the next 25 years, 51.2 million measles cases could occur due to the decline in childhood vaccination.

That number requires context. It's a projection, not a prediction—based on current trends continuing without intervention. It assumes no major policy changes, no renewed public health campaigns, no shift in public attitudes.

But projections matter because they clarify stakes. They show us the world we're building through our collective choices.

The Paradox of Success

The measles resurgence illustrates a cruel irony in public health: success breeds complacency.

When a disease is common, people fear it. They've seen children die. They've known families devastated by complications. They line up for vaccines the moment they become available.

But when vaccines work—when they work so well that a disease virtually disappears—the calculus shifts. Parents born after elimination have never seen a child with measles. The disease becomes abstract, historical, someone else's problem. Meanwhile, the vaccine remains concrete: a needle, a crying child, and, for some, a fog of internet misinformation suggesting it might cause more harm than the disease it prevents.

This is the trap. Vaccines become victims of their own success. The more effectively they protect us, the less urgently we feel the need for protection.

What Ninety-Seven Percent Effectiveness Actually Means

The recommended measles vaccination protocol involves two doses, given at least one month apart. A single dose is 93 percent effective at preventing measles. Two doses raise that to 97 percent.

Ninety-seven percent sounds nearly perfect. But consider what it means at population scale.

If a million people receive two doses of the vaccine, roughly 30,000 of them—3 percent—won't develop full immunity. Most of these people will still have partial protection; if they catch measles, their cases will likely be milder. But some will remain genuinely vulnerable.

This is why herd immunity matters. The 97 percent who are protected form a shield around the 3 percent who aren't. When vaccination rates are high enough, the virus can't find paths through the community. It hits immune person after immune person and dies out.

When vaccination rates fall, those paths open. The 3 percent who didn't develop immunity—plus infants too young to be vaccinated, plus people with immune conditions who can't receive vaccines, plus those who simply never got around to it—suddenly face exposure.

The math is unforgiving. In a population where 95 percent are immune, measles fizzles out. In a population where 85 percent are immune, it smolders. In a population where 75 percent are immune, it blazes.

The Disease We Forgot to Fear

Before the vaccine became available in 1963, American parents lived with a grim understanding: their children would almost certainly catch measles, and some of them would die.

The last major pre-elimination outbreak ran from 1989 to 1991. It killed 123 people. The majority were preschool children.

Today, we've lost that visceral memory. We've lost the understanding that measles isn't a harmless childhood illness, like a cold or a mild flu. It's a disease that kills, that causes brain damage, that leaves survivors with lasting complications.

The World Health Organization has expressed concern that it may need to rescind the United States' measles elimination status. Twenty-five years of protection, built through one of the greatest public health achievements in history, now hangs in the balance.

Whether we keep that status—whether we reverse the trend or accelerate into more outbreaks and more deaths—depends on choices being made right now, in doctor's offices and school board meetings and state legislatures, in conversations between parents and pediatricians, in the quiet moment when a mother or father decides whether to schedule that vaccine appointment.

The virus, meanwhile, waits. It doesn't care about our debates. It doesn't follow our politics. It simply does what it has always done: find the unprotected and spread.