Pfizer Vaccine Linked to Higher Death Rates Than Moderna in Florida Study

New Study Raises Concerns About Pfizer Vaccine

A recent study conducted in Florida has sparked concern among health officials and the public, revealing that adults who received the Pfizer COVID-19 vaccine experienced higher death rates than those who received the Moderna vaccine. The research, led by Florida Surgeon General Dr. Joseph Ladapo and MIT professor Retsef Levi, analyzed data from nearly 1.5 million Floridians. The study focused on adults who received two doses of either vaccine between December 18, 2020, and August 31, 2021, and tracked their outcomes over the following 12 months.

The findings, published as a preprint on medRxiv on April 29, showed that Pfizer recipients had a significantly higher risk of death from all causes, including heart-related issues and COVID-19 itself. Specifically, the study reported 847 deaths per 100,000 Pfizer recipients compared to 618 deaths per 100,000 Moderna recipients. This discrepancy has raised questions about the safety and effectiveness of the Pfizer vaccine, prompting calls for further investigation.

Detailed Findings and Methodology

The study involved a matched cohort of 1,470,100 noninstitutionalized Florida adults, with 735,050 receiving Pfizer and an equal number receiving Moderna. Researchers used state-level public health databases to ensure precise matching based on factors like age, sex, and census tract. This approach aimed to eliminate variables that could skew results, making the comparison between the two vaccines as fair as possible.

According to Dr. Joseph Ladapo, 'These findings are suggestive of differential non-specific effects of the [Pfizer and Moderna] COVID-19 vaccines, and potential concerning adverse effects on all-cause and cardiovascular mortality.' The study found that Pfizer recipients faced a 37% higher risk of all-cause death, a 53% higher risk of cardiovascular death, and an 88% higher risk of COVID-19 death compared to Moderna recipients. Non-COVID-19 deaths were also 35% higher among Pfizer recipients, a statistic that has alarmed researchers.

The researchers noted that their study differs from previous analyses due to its large sample size and rigorous matching criteria. Earlier studies, such as one published in 2023 using clinical trial data, found no significant impact on all-cause mortality for either vaccine but noted increased heart-related deaths among vaccinated individuals, which offset COVID-19 protection.

Possible Explanations and Implications

One surprising aspect of the study is that Moderna’s vaccine, which contains approximately three times more mRNA (100 µg) than Pfizer’s (30 µg), was associated with lower mortality. Researchers, including Retsef Levi, speculated that other factors, such as potential DNA contamination in Pfizer’s vaccine, might contribute to the observed differences. 'The findings of this study are surprising, given that Moderna’s [vaccine] contains approximately three times more mRNA,' Levi stated, highlighting the need for further research into vaccine composition.

The study’s authors emphasized that their findings do not negate the overall benefits of vaccination but underscore the importance of evaluating vaccines beyond their targeted disease. They called for clinical endpoints that assess broader health impacts, particularly given the significant differences in outcomes between the two vaccines.

Public Health Response and Next Steps

Florida’s health officials have taken the study seriously, with Dr. Ladapo advocating for transparency in vaccine safety discussions. The findings have prompted some to question whether public health messaging should differentiate between Pfizer and Moderna vaccines, especially for older adults who appear to be at higher risk. Previous research, such as a 2023 study in Milwaukee County, also found that Pfizer recipients aged 60 and older had a mortality risk over twice that of Moderna recipients, lending credence to the Florida study’s conclusions.

Health authorities are now faced with the challenge of addressing these findings without causing undue alarm. The study’s preprint status means it has not yet been peer-reviewed, but its large sample size and detailed methodology have garnered attention. Researchers are urging federal agencies to conduct follow-up studies to confirm the results and explore potential causes, such as differences in vaccine formulation or manufacturing processes.

As the debate continues, the study serves as a reminder of the importance of ongoing vigilance in monitoring vaccine safety. For now, health officials are encouraging individuals to consult with their doctors to make informed decisions about vaccination, particularly in light of these new findings.