A large-scale study conducted in Florida is reigniting debate over the safety and comparative efficacy of COVID-19 vaccines. Researchers from the Massachusetts Institute of Technology (MIT), in collaboration with Florida’s top health officials, analyzed data from over 1.4 million vaccinated individuals and found that those who received the Moderna vaccine had a notably lower all-cause mortality rate than those vaccinated with Pfizer.

The study, which spans the vaccination period from December 2020 to August 2021, compared two matched groups of adults: one vaccinated with at least two doses of Moderna (mRNA-1273), and the other with at least two doses of Pfizer (BNT162b2). Researchers controlled for seven demographic and geographical factors, including age, gender, race, ethnicity, vaccination site, time of vaccination, and county of residence.

Key Findings: 40% Higher Mortality Among Pfizer Group

The data revealed a striking difference in mortality rates. Among every 100,000 individuals vaccinated with Pfizer, 847 had died from all causes within a year of vaccination, compared to 618 deaths per 100,000 among Moderna recipients. That equates to a difference of nearly 230 deaths per 100,000 individuals—around a 27% higher rate for Pfizer.

When broken down further, the contrast was even more pronounced in specific categories. The study reports a 40% to 50% higher death rate from cardiovascular causes and COVID-related mortality in the Pfizer group compared to Moderna.

Florida Surgeon General Dr. Joseph Ladapo, who co-authored the study, shared the findings on the social platform X, stating, “Did your doctor tell you that your risk of dying is higher with Pfizer than Moderna? That’s what we discovered in Florida—and other studies have shown similar patterns.”

Calls for Caution, Controversy Remains

Dr. Ladapo, along with MIT professor Retsef Levi, has previously raised concerns about both Pfizer and Moderna vaccines, advocating for halting further COVID-19 immunizations until more data is available. They referenced earlier studies from 2023 suggesting that while these mRNA vaccines reduced death from COVID-19, they may have had an offsetting rise in deaths due to cardiac complications—leading to little or no net change in all-cause mortality.

However, the latest study has not yet undergone peer review, and medical experts are urging the public and policymakers to interpret its findings with caution.

What Critics Are Saying

One of the main criticisms is that the study does not compare vaccinated individuals to unvaccinated ones—a vital piece of context that could shape the interpretation of mortality figures. Without that comparison, it’s unclear whether the mortality rates observed are higher, lower, or the same as those in the general unvaccinated population.

Other analysts have pointed out that the Pfizer group’s mortality rate (847 per 100,000) closely mirrors Florida’s general mortality rate in 2021 (833 per 100,000), suggesting that the observed numbers may not be abnormally high but instead reflect the baseline risk.

“This study raises important questions, but it also has significant limitations,” said Dr. Angela Roberts, a public health expert at Johns Hopkins University. “Until it’s peer-reviewed and placed in the broader context of other research, it would be premature to draw strong conclusions about vaccine safety or efficacy.”

A Polarizing Messenger

Dr. Ladapo’s role in promoting the study adds a layer of political complexity. Appointed by Florida Governor Ron DeSantis, Ladapo has frequently made headlines for his unconventional and skeptical views on vaccines and pandemic mitigation. His public stance has drawn sharp criticism from national health agencies and praise from vaccine skeptics.

Nevertheless, the study’s conclusions—if validated—could have far-reaching implications. With over 600 million doses of COVID-19 vaccines administered in the U.S. since 2020, even small differences in outcomes between vaccine types could affect future public health guidance, booster campaign strategies, and informed consent protocols.

Final Word: Transparency Needed

For now, the study remains a preprint, awaiting peer review and broader scientific scrutiny. As more data becomes available, the medical community will be tasked with reconciling conflicting studies and balancing risk-benefit assessments that continue to evolve.

One thing is certain: vaccine safety remains a subject of urgent public interest. And with studies like this one stirring both alarm and skepticism, transparency, robust data analysis, and open scientific debate are more essential than ever.