Florida’s vulnerability to measles is approaching a critical tipping point, with new analytical findings showing that the state could face a devastating public health crisis if vaccination rates drop further. According to an analysis published in PNAS, falling coverage of the measles, mumps, and rubella (MMR) vaccination among kindergarteners over the past decade has left certain schools exposed to potential outbreaks that could carry severe consequences.
Measles remains the most contagious disease known to humanity. Data from the Centers for Disease Control and Prevention (CDC) indicate that if a single person has the virus, roughly 9 out of 10 unprotected individuals nearby will contract it. The World Health Organization has made this statement about one infected person potentially infecting up to 18 others. In severe infections, one to three of every 1,000 children who contract measles will likely die from respiratory and neurological complications.
Mathematical Modeling Predicts Severe Repercussions
A mathematical model developed at the University of Maryland (UMD) warns that if Florida eliminates its requirement for public school students to receive the MMR vaccine—a proposal put forward by the state’s surgeon general—the state could experience an even sharper decline in vaccination coverage. This drop could result in dozens, if not hundreds, of preventable child deaths over the following five to 10 years.
“As someone who has lost a child, not to a disease, but I have lost a child, that’s not something I could wish on anyone,” said lead author Alice Oveson, a PhD student in UMD’s applied math program. Oveson worked alongside UMD mathematician Abba Gumel, PhD, utilizing data from a 2025 measles outbreak in Gaines County, Texas, to build a transmission model tailored to Florida’s demographics, MMR coverage rates, and contact rates.
For the 2025-26 school year, CDC figures show that Florida’s MMR vaccination rate for kindergarteners stands at 88.9%. Under a worst-case scenario where coverage drops to 82%, the model projects that the state would suffer a pronounced measles outbreak within five to 10 years. Disease levels under this projection would exceed any recorded in the United States since 1977, with estimated infections ranging from 260 to 315 cases per 100,000 children. Achieving the herd immunity threshold required to prevent outbreaks demands a vaccination rate of 95%.
Evaluating Prevention Strategies and Model Limitations
Despite Florida being one of the oldest states in the country—with 80% of its population over the age of 40—the UMD model revealed that vaccinating a single child is three times more effective at reducing transmission than vaccinating an adult. This dynamic stems from higher baseline immunity among older populations combined with closer physical contact among school-aged children. If kindergarten vaccination coverage remains steady at 88.9%, short-term interventions such as isolation and masking could still substantially curb the epidemic burden, according to the study.
However, external experts have raised questions regarding the model’s operational utility. Matthew Ferrari, PhD, director of Penn State’s Center for Infectious Disease Dynamics, argued that the UMD model falls short in several key areas. Ferrari noted that grouping all Floridians into just two age brackets—under and over 18—is overly simplistic, missing specific risks to infants who are too young to be vaccinated. He also pointed out that the study does not account for Florida’s vast geographic diversity, seasonal measles spikes during winter and early spring, or the fact that full immunization requires two doses of the MMR vaccine rather than the single dose factored into the model. Ferrari characterized the findings on masking and isolation as speculative, stating that the paper adds little to the operational understanding of measles control.
Nationwide, measles transmission has remained a prominent concern, with multiple outbreaks resulting in more than 3,600 confirmed cases across the United States in 2026—marking the highest total in 35 years. Pennsylvania recently announced its fifth measles-associated death in Lancaster County, the epicenter of that state’s outbreak.
Related reading
