The United States is inching dangerously close to a public health crisis as falling childhood immunization rates threaten to make measles endemic once again, scientists warn. A new study by researchers at Stanford University’s School of Medicine has modeled the long-term impact of declining vaccine coverage, revealing stark predictions if current trends persist.
According to Dr. Nathan Lo and Dr. Mathew Kiang, even small reductions in vaccination rates could lead to hundreds of thousands of measles cases, tens of thousands of hospitalizations, and thousands of deaths over the next few decades. Their study, published in the Journal of the American Medical Association, comes at a time when vaccine hesitancy has gained a stronger foothold in the US.
“This is a slow-moving crisis,” said Kiang, an assistant professor of epidemiology and population health. “If we just keep going the way we are, bad things are going to happen within about two decades.”
From Elimination to Re-Emergence: A Sobering Outlook
Measles was declared eliminated from the United States in 2000, meaning that widespread vaccination had made local transmission extremely rare. Although imported cases occasionally triggered small outbreaks, the country had maintained herd immunity levels high enough to prevent endemic spread.
However, since the onset of the COVID-19 pandemic, routine childhood immunization rates have been steadily declining. National coverage for the measles, mumps, and rubella (MMR) vaccine dropped from around 95% before 2020 to less than 93% during the 2023–24 school year.
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While a 2% decline may seem minor, it has major implications for a disease as contagious as measles. Lo and Kiang’s model projects that, under current vaccination rates, the US would see measles become endemic again within 25 years. Their estimates suggest up to 851,300 measles cases could occur between now and 2050, alongside 170,000 hospitalizations and approximately 2,550 deaths.
Far-Reaching Impacts Beyond Measles
Although measles poses the greatest risk due to its high transmissibility, the researchers also modeled the potential return of other vaccine-preventable diseases. Their projections include 190 cases of rubella, 18 cases of poliomyelitis, and eight cases of diphtheria during the same period.
Parents would no longer be able to rely on herd immunity to protect vulnerable populations, such as infants too young to be vaccinated. Pediatricians and emergency rooms, many of which have not treated measles cases for decades, would be confronted with severe complications including pneumonia, encephalitis, and even death.
“We are talking about losing decades of public health progress,” said Dr. Adam Ratner, a pediatric infectious-disease specialist in New York City who praised the Stanford team’s study as “exceptional” in its clarity and urgency.
Small Gains Could Yield Big Results
There is a bright side, however. The study also showed that relatively modest increases in vaccination coverage could prevent a resurgence of measles and other diseases. If MMR vaccination rates were to increase by just 5%, the number of measles cases projected through 2050 would be halved compared to the previous 25 years.
“A small fraction of the population here can really make the difference in terms of tipping us into more safe areas,” said Lo, an assistant professor of infectious diseases. “We don’t need miracles — we just need modest improvements.”
Such findings reinforce the importance of public health messaging and community outreach efforts aimed at increasing vaccination uptake, particularly among hesitant or underserved communities.
Vaccine Hesitancy and Political Shifts Fuel Concern
While modest gains in immunization could yield profound benefits, Lo and Kiang are deeply concerned that the opposite may happen. In recent months, shifts in national leadership have heightened anxieties about future vaccination policy.
Since President Trump’s return to office in January 2025, he has appointed Robert F. Kennedy Jr. as secretary of Health and Human Services, a figure long associated with anti-vaccine rhetoric. Although Kennedy pledged during his confirmation hearings not to change the childhood immunization schedule, he later announced plans to investigate vaccines, raising fears among public health experts of undermining confidence further.
“If vaccination rates fall another 25%, we could be looking at nearly 27 million measles cases and over 80,000 deaths from vaccine-preventable diseases,” Kiang warned.
A decline of that magnitude would mark an unprecedented public health disaster. Under such a scenario, the United States would see measles become endemic within just five years, with 51.2 million cases of measles, 9.9 million cases of rubella, 4.3 million cases of polio, and more than 159,000 deaths projected over the next quarter-century.
“These are diseases that U.S. families are not used to thinking about or seeing, and they may become commonplace again in the near future unless we reverse course,” Ratner said.
A Bleak Future Without Action
The consequences of declining vaccination rates extend beyond mortality statistics. Thousands of children could suffer devastating long-term disabilities. The Stanford team projects that if vaccination rates drop by half, some 51,000 children would experience life-altering neurological complications, and 5,400 would be paralyzed by polio—a disease for which there have been no reported US cases since 1993.
“To put this in perspective, most physicians in the U.S. haven’t seen a single case of any of these diseases because we have very effective vaccines,” said Dr. Kristina Bryant, a pediatric infectious diseases specialist at Norton Children’s Hospital in Louisville, Kentucky.
The return of diseases like polio would strain already burdened healthcare systems and require a renewed investment in rehabilitation services, long-term care, and costly public health interventions.
The Urgent Need for Public Health Action
Experts emphasize that time is running out to reverse these trends. With vaccination skepticism increasingly mainstreamed into political discourse and amplified by social media misinformation, maintaining — let alone boosting — immunization rates poses a significant challenge.
“This isn’t inevitable,” Lo said. “We can prevent this future. But it’s going to take concerted, consistent effort from all sectors of society — political leaders, healthcare providers, educators, and parents alike.”
Samaras added, “What we’ve learned over the past few months is that our imagination needs to be larger for what is possible in public health disasters.”
If decisive action is not taken soon, America could find itself facing a resurgence of deadly, preventable diseases it once conquered — a sobering testament to the consequences of complacency.
Conclusion: A Call to Defend Decades of Progress
The warnings from Stanford’s research team are clear: the United States stands at a critical crossroads. Without immediate efforts to rebuild public trust in vaccines and boost immunization coverage, the nation risks returning to an era when deadly infectious diseases were an everyday reality.
The reemergence of measles would be more than a public health failure—it would be a profound societal loss. The future depends on renewed commitment to science, public health, and the collective protection of every vulnerable life.
