Recent reports highlighting an increase in U.S. measles cases are frequently tied to discussions surrounding eroding public trust in immunizations.
While researchers are careful to distinguish between correlation (where two trends are associated) and causation (where one directly triggers the other), data indicates a clear behavioral link in the United States: parents who harbor doubts regarding the safety, efficacy, or necessity of vaccines are far less likely to keep their children fully immunized.
“There’s a clear correlation there,” notes Lunna Lopes, a senior survey manager at the health policy organization KFF. “That relationship remains significant even when we control for variables like age, education level, and political affiliation.”
This downward trend in routine vaccinations brings entirely predictable outcomes. Measles—a virus that the U.S. officially declared “eliminated” back in 2000—has seen a resurgence over recent years. According to figures from the Centers for Disease Control and Prevention, the nation logged nearly 500 more measles cases in the first eight months of 2026 than it did throughout the entirety of 2025.
Pinpointing the exact drivers behind the rise of these vaccine-preventable diseases is complex, but a closer look at the data helps clarify the broader picture through several key trends.
U.S. Vaccination Trends
The CDC reported a 0.1% overall decline in vaccination coverage among incoming kindergarten students for the 2025-26 academic year.
This dip aligns with a broader, steady decline in kindergarten vaccination rates across nearly all vaccine types that has persisted since the onset of the COVID-19 pandemic.
Public health experts emphasize that even fractional percentage drops mean thousands of children are left without protection. For instance, roughly 280,000 kindergartners entered schools during the 2025–26 term without official documentation of completing the measles, mumps, and rubella (MMR) vaccine series.
Robin Mejia, a biostatistics professor at the University of Washington School of Public Health, points out that a national 0.1% drop does not manifest evenly across the country.
“You see sharp, localized drops in specific regions and school districts, while other areas experience virtually no change,” Mejia explained. “It is precisely these pockets of low coverage that allow diseases like measles to gain a foothold and spread.”
Furthermore, CDC figures show that a growing proportion of parents sought exemptions allowing their children to attend school without standard immunizations during the 2025–26 school year.
While medical exemption requests have remained stable over the years, non-medical exemptions have climbed steadily since the 2020–21 school term, mirroring the general drop in MMR coverage rates.
Epidemiologists calculate that approximately 95% of a population must be vaccinated against MMR to maintain herd immunity and halt community transmission. During the 2025–26 academic year, only 10 states met or exceeded that critical benchmark.
The consequences are tangible: the U.S. has recorded more than 2,700 measles cases thus far in 2026. The CDC reports that 94% of these patients were either entirely unvaccinated or had an unknown vaccination history.
In 2025, the virus claimed the lives of two school-aged children and one adult—all of whom were unvaccinated at the time of infection.
More recently, health authorities in Pennsylvania confirmed two measles-linked deaths among unvaccinated individuals. One case involved a newborn; while the local coroner attributed the official cause of death to an internal hemorrhage and a ruptured spleen—and noted the presence of the measles virus in lung tissue—experts acknowledge that the precise impact of the infection on the infant’s passing remains difficult to fully quantify.
Misinformation and Vaccine Hesitancy
Since 2015, monitoring by the Vaccine Confidence Project has revealed shifting public agreement with statements like “vaccines are safe” and “vaccines align with my personal beliefs.”
By 2023, public endorsement for the ideas that vaccines are essential for children, safe, and effective had dropped notably compared to 2015 levels.
While isolating the exact role that myths play in healthcare choices is challenging, survey data published by KFF in May 2026 highlights a direct statistical link between belief in false vaccine claims and decisions to postpone or forgo immunizations.
Parents who admitted to skipping or delaying their children’s shots were roughly twice as likely to view specific vaccine myths as “definitely” or “probably true.”
According to KFF’s Lopes, only a small fraction of the population categorizes these widespread myths as absolute truth.
“Instead, what we observe is a large segment of the population residing in a sort of muddled middle,” Lopes explained. These individuals may not fully endorse or reject misinformation outright, often leaning toward describing false claims as simply “probably true” or “probably false.”
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