US Measles Elimination at Risk as Childhood Vaccination Rates Decline

BELLEVUE, WA – January 02, 2026 – As the United States grapples with the highest number of measles cases in over three decades, new research published in JAMA Network Open reveals a troubling decline in the timeliness of childhood immunizations, placing the nation’s long-held measles elimination status in jeopardy.

The landmark study, conducted by the real-world intelligence company Truveta, analyzed the de-identified health records of over 320,000 children and found a significant drop in on-time measles, mumps, and rubella (MMR) vaccinations since the COVID-19 pandemic. More critically, the research identifies a crucial early warning sign: infants who are late for their recommended 2- and 4-month vaccine doses are up to seven times more likely to miss their first MMR shot entirely.

These findings provide a stark data-driven backdrop to a burgeoning public health crisis. In 2025 alone, the U.S. reported 2,065 measles cases, a figure not seen since 1992. The outbreaks, which included the first measles-related deaths in a decade, have pushed the country to the brink of losing the measles elimination status it has maintained since 2000.

A Widening Gap in Protection

The research quantifies a concerning trend that public health officials have feared. According to the study, the rate of children receiving their first MMR dose on schedule—between 12 and 15 months of age—fell by three percentage points, from 79.9% in 2021 to just 76.9% in 2024. Simultaneously, the percentage of children who had received no MMR vaccine at all by age two climbed from 5.3% in 2020 to 7.7% in 2024.

This decline coincides with a broader erosion of vaccination coverage. National rates for kindergarteners have fallen below the 95% threshold required for herd immunity against measles, a highly contagious virus that can lead to severe complications, including pneumonia, brain damage, and death. With 92% of the 2025 measles cases occurring in unvaccinated individuals or those with unknown status, the real-world consequences of these vaccination gaps are becoming tragically clear.

The study’s authors note that the downward trend isn't limited to the MMR vaccine, observing similar delays across multiple early-childhood immunizations. This signals a more systemic issue, fueled by factors ranging from healthcare disruptions during the pandemic to the pervasive spread of vaccine hesitancy and misinformation online. Public opinion has shifted, with recent polling showing a significant drop in the number of Americans who view childhood vaccines as critically important compared to two decades ago.

An Early Warning for Parents and Doctors

Beyond sounding the alarm, the Truveta study offers a vital, actionable insight for reversing the trend. The research pinpoints a child's earliest vaccination appointments as the strongest predictor of their future immunization status. Children who were delayed in receiving their 2-month vaccines were nearly seven times more likely to have no MMR vaccine by age two. A delay at the 4-month mark increased the odds more than sixfold.

This discovery effectively creates an early warning system for pediatricians and parents. It reframes a simple scheduling delay as a critical indicator of potential long-term under-vaccination, providing a crucial opportunity for intervention.

“This research reinforces that parents’ decisions to vaccinate their children are not isolated moments—but rather a trajectory that begins in infancy,” said Nina Masters, PhD, MPH, Senior Applied Research Scientist at Truveta and a lead author of the study. “Identifying vaccination delays early gives pediatricians an opportunity to engage families sooner, address hesitancy with evidence and compassion, and help keep children on track before gaps in protection widen. This is especially important in the context of misinformation and changing federal vaccine policy.”

By focusing on the first few months of a child’s life, healthcare providers can initiate conversations, understand parental concerns, and reinforce the importance of the recommended immunization schedule before a child becomes vulnerable to preventable diseases.

The Power of Real-World Data

The study’s ability to generate such timely and specific insights stems from its innovative use of real-world data. Leveraging a massive, de-identified dataset drawn from the electronic health records of over 120 million Americans across more than 30 health systems, the research firm was able to analyze recent trends with a level of speed and granularity that traditional public health surveillance methods often cannot match.

This approach allows for near real-time monitoring of public health trends, illuminating emerging problems as they happen. It provides an unvarnished look into how healthcare is delivered and received across a vast and diverse population, offering insights that are essential for crafting effective public health strategies.

“Reliable data plays a critical role in rebuilding trust around childhood vaccination,” said Brianna Cartwright, MS, Principal Research Analyst at Truveta. “By illuminating where and when children begin to fall behind, this research helps clinicians have more informed, confident conversations with parents—and helps public health agencies focus resources where they can have the greatest impact.”

Charting a Path Forward

With measles outbreaks becoming more frequent and the threat to national elimination status looming, the study’s findings underscore the urgent need for a multi-pronged response. Public health leaders like the Centers for Disease Control and Prevention (CDC) have already called for targeted approaches to close immunity gaps, particularly in undervaccinated communities, and for reinforcing vaccination recommendations before international travel, a common source of measles importation.

This new research adds a critical tool to that effort. By empowering pediatricians to identify at-risk children months before their first MMR shot is even due, the healthcare system can shift from a reactive to a proactive stance. The focus can move toward early education, consistent scheduling, and compassionate dialogue to counter hesitancy. This approach is vital for ensuring that preventable diseases like measles do not stage a permanent comeback, threatening a new generation of children who have largely been protected for decades. The data provides a clear warning and a potential solution, placing the responsibility on the healthcare community to act before more ground is lost.