According to a new study, adults who received the Pfizer Comirnaty COVID-19 shot were more likely to die than adults who had the Moderna Spikevax COVID-19 shot. The study looked at 9.2 million adults living in Florida who received either Comirnaty or Spikevax within six weeks, from December 2020 through January 20221. Half of the nearly 1.5 million participants received the Pfizer shot and the other half had the Moderna shot. Participants were matched based on age and gender.1
The study, “Twelve-Month All-Cause Mortality after Initial COVID-19 Vaccination with Pfizer-BioNTech or mRNA-1273 among Adults Living in Florida” was conducted by Florida Surgeon General, Joseph Ladapo, MD, and Retsef Levi, PhD of the Massachusetts Institute of Technology (MIT), as well as two other researchers. The study is in preprint and has not yet been peer-reviewed.2
Pfizer Shot Causes Significantly Higher All-Cause Death
Participants were compared 12 months after their first dose of the COVID shots. Researchers looked at all-cause mortality, cardiovascular mortality, and COVID mortality, together with non-COVID causes of death which occurred within 12 months after participants received a shot.
In terms of all-cause mortality, participants who received the Pfizer shot had a 37 percent higher risk than Moderna shot recipients. The risk for those who received the Pfizer shot was 847.2 and 617.9 for Moderna shot recipients per 100,000 people. Therefore, there were 229.2 excess deaths per 100,000 people in the Pfizer group than in the Moderna group.3
In terms of death due to cardiovascular events, the risk for those who took the Pfizer shot increases to 53 percent. There were 248.7 cardiovascular deaths in the Pfizer group and 162.4 deaths in the Moderna group with a difference of 86.3 extra deaths per 100,000 people in the Pfizer group.4
Pfizer shot recipients faced almost double the risk of dying from the COVID virus itself than Moderna shot recipients. In the Pfizer group there were 55.5 deaths and in the Moderna group there were 29.5 deaths among 100,000 people. Accordingly, there were 26 more deaths per 100,000 people in the Pfizer group.5
There was a 35 percent greater chance of dying from non-COVID related causes for Pfizer patients compared to Moderna patients. The risk of dying after getting the Pfizer shot was 791.6 and 588.4 in the Moderna group per 100,000 people. Pfizer had a 203.3 excess death rate than Moderna.6
Pfizer Shot May Cause Higher Level of DNA Contamination
While both biologics were produced using mRNA technology, each product has key differences. The Pfizer shot has 30 ug of mRNA while the Moderna shot contains 100 ug of mRNA. Moderna requires a four- week interval between doses while Pfizer recommends a three-week interval between doses. The composition of the lipid nanoparticles that coat the mRNA delivered into the cells of the body by the Pfizer and Moderna biological products are also different.7
Since the Moderna shot has three times as much mRNA as the Pfizer shot, it is unlikely that the amount of mRNA is what is driving the higher mortality rate. There is speculation that the higher mortality rate could be due to the Pfizer shot containing a higher level of DNA contamination due different composition of the lipid nanoparticles used by Pfizer, as well as differences in manufacturing, biodistribution or storage conditions.8
Current Study Different from Previous Studies Comparing the COVID Shots
The researchers addressed three previous studies comparing the two top mRNA COVID shots which have been relied upon by the Department of Veteran Affairs. The New England Journal of Medicine 2021 study compared the Pfizer and Moderna shots in 219,842 recipients over a period of 24 weeks. This study showed that patients who took the Pfizer shot were more likely to be hospitalized or die from COVID disease than Moderna shot patients.9 10
A 2023 study looking at mortality and vaccination records of Pfizer and Moderna patients found that among 442,088 COVID shot recipients, Pfizer patients faced a greater risk of heart attack and stroke after vaccination.11 12
The authors of the recent study differentiated their findings from previous studies based on the fact that as it had a much larger study group and the matching of the two groups was more precise.
Florida Surgeon General Advocated for Suspending the COVID Shots
In 2024, Dr. Ladapo called for the suspension of the mRNA COVID shots citing his concerns regarding the discovery of DNA contaminantion of the mRNA biologicals. He pointed out that the inclusion of lipid nanoparticle complexes and simian virus 40 (SV40) promoter/enhancer DNA as being particularly concerning. The lipid nanoparticles act as an “efficient vehicle” to drive mRNA into cells and could also deliver contaminant DNA, as well affecting, “the integrity of the human genome.” The U.S. Food and Drug administration (FDA) and U.S. Centers for Disease Control (CDC) disagreed with Ladapo’s claims and denied that the mRNA shots could alter recipients DNA and were unsafe.13 14 15
In response to this study, Ladapo asked:
Did your doctor tell you that you might be more likely to die if you took Pfizer instead of Moderna? That’s what we found in Florida, and other studies have shown similar results.16
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Click here to view References:1 Stieber Z. Recipients of Pfizer COVID-19 Vaccine Had Higher Mortality Than Those of Moderna: Study. The Epoch Times May, 2, 2025.
2 Hulscher N. NEW STUDY — Pfizer Recipients Face 37% Higher Risk of Death Than Moderna Recipients. Public Health Policy Journal.
3 Ibid.
4 Ibid.
5 Ibid.
6 Ibid.
7 Dickerman B, Gerlovin H, Madenci AL et al. Comparative Effectiveness of BNT162b2 and mRNA-1273 Vaccines in U.S. Veterans. New England Journal of Medicine Dec. 1, 2021.
8 Hulscher N. NEW STUDY — Pfizer Recipients Face 37% Higher Risk of Death Than Moderna Recipients. Public Health Policy Journal.
9 Stieber Z. Recipients of Pfizer COVID-19 Vaccine Had Higher Mortality Than Those of Moderna: Study. The Epoch Times May, 2, 2025.
10 Dickerman B, Gerlovin H, Madenci AL et al. Comparative Effectiveness of BNT162b2 and mRNA-1273 Vaccines in U.S. Veterans. New England Journal of Medicine Dec. 1, 2021.
11 Stieber Z. Recipients of Pfizer COVID-19 Vaccine Had Higher Mortality Than Those of Moderna: Study. The Epoch Times May, 2, 2025.
12 Atanasov V, Barreto N, Whittle J et al. Selection Effects and COVID-19 Mortality Risk after Pfizer vs. Moderna Vaccination: Evidence from Linked Mortality and Vaccination Records. Vaccines May 11, 2023.
13 Anderson Z. Florida Surgeon General Ladapo contradicts feds, recommends against mRNA COVID shots. Sarasota Herald-Tribune Jan. 3, 2024.
14 Armstrong K. Florida Surgeon General calls on FDA to halt COVID-19 vaccines, citing possible cancer risks: FDA disagrees. Fox 35 Orlando Jan. 4, 2004.
15 Mesmer A. Florida Surgeon General calls for halt on mRNA COVID-19 vaccines. Fox 13 Tampa Bay Jan. 3, 2024.
16 Stieber Z. Recipients of Pfizer COVID-19 Vaccine Had Higher Mortality Than Those of Moderna: Study. The Epoch Times May, 2, 2025.
