The Pfizer and Moderna COVID-19 vaccines, which are based on messenger RNA (mRNA) technology, do not affect overall mortality, according to a reanalysis of clinical trial data.
Researchers, including Christine Stabell Benn, a health professor at the University of Southern Denmark, published their findings in the Cell journal in April. The study revealed that although the mRNA vaccines protected against COVID-19-related deaths, vaccinated participants were more likely to die from cardiovascular problems.
“In the RCTs with the longest possible blinded follow-up, mRNA vaccines had no effect on overall mortality despite protecting against some COVID-19 deaths. On the other hand, the adenovirus-vector vaccines were associated with lower overall mortality,” researchers said.
“The differences in the effects of adenovirus-vector and mRNA vaccines on overall mortality, if true, would have a major impact on global health,” they added later.
Benn and her colleagues extracted data from three RCTs for the mRNA vaccines and six RCTs for the adenovirus-vector vaccines, all of which had mortality data available. They compared the number of deaths between the vaccinated and placebo groups, categorizing them as COVID-19-related, due to cardiovascular problems, caused by other non-COVID-19 factors, accidents, and non-accident, non-COVID-19 causes.
The research involved analyzing data from randomized clinical trials (RCTs) conducted by the vaccine manufacturers. Requests for comment from Pfizer, Moderna, Johnson & Johnson, and AstraZeneca went unanswered.
The researchers found that the Pfizer and Moderna vaccines were linked to a decrease in COVID-19 mortality but an increase in cardiovascular and non-accident, non-COVID-19 mortality. However, there was no difference in overall mortality between the vaccinated and placebo groups.
Regarding the Johnson & Johnson vaccine, it was associated with lower overall mortality and lower non-COVID-19 mortality, with no effect on COVID-19 mortality. AstraZeneca’s vaccine, which was not authorized in the United States but approved in some other countries, performed well against overall mortality and across various categories in several trials, except for one trial where slightly more vaccinated individuals died from non-COVID causes or non-accident, non-COVID-19 causes.
The researchers stated that adenovirus-vector vaccines, compared to placebos, appeared to have beneficial non-specific effects, reducing the risk of non-COVID-19 diseases. Cardiovascular disease was identified as the most significant cause of non-COVID-19 death, and the data from current RCTs suggested that adenovirus-vector vaccines provided at least some protection against it.
The study was published in 2022, ahead of peer review, but faced difficulties finding a journal that would accept it for publication. Benn stated that several journals rejected the paper without providing an explanation, leading to delays in publication.
After the rollout of vaccines, including highly vaccinated countries like the United States, there was an increase in overall mortality. The causes of this increase are still debated among researchers, with some attributing it primarily to the vaccines and others citing COVID-19 and other factors.
Dr. Peter Gotzsche, professor emeritus and director of the Institute for Scientific Freedom in Denmark, commended the paper, calling it ‘thought-provoking.’
Dr. David Boulware, a professor of medicine at the University of Minnesota’s Medical School, raised concerns about the methodology of the new study. In an email to The Epoch Times, he stated that the study was poorly designed due to variations in the locations where the trials took place. Boulware argued that countries with better healthcare, such as the United States, may have influenced the results.
The researchers themselves acknowledged this potential limitation in the study, stating in the limitations section that “differences between the study populations in the RCTs of the two vaccine types could have biased the comparison as different disease patterns and level of care could have influenced the measured effect of the vaccines on overall mortality.”
Furthermore, the researchers noted that in the mRNA clinical trials, more individuals were infected with COVID-19 compared to the adenovirus-vector vaccine trials, yet there were more COVID-19 deaths in the adenovirus-vector trials. This suggests that participants in the mRNA trials may have had access to better healthcare during COVID-19 infection, which could have impacted the measured effect of mRNA vaccination on overall mortality.
Boulware also pointed to real-world data, including observational data from Israel and Minnesota, which he believes contradicts the conclusions of the paper. He stated that mRNA vaccines clearly provide better protection against COVID-19 compared to adenovirus vector vaccines.
In response, Benn defended the study, emphasizing that it was based on a meta-analysis of placebo-controlled randomized clinical trials, which is considered the highest level of evidence. Randomized clinical trials data is considered the “gold standard” for medical research. The primary focus of the study, according to Benn, was overall mortality.
“He is discussing COVID-19—we are studying all-cause mortality,” Benn stated. “It is irrelevant if a vaccine protects better against COVID-19 than another vaccine if it reduces overall mortality to a lesser degree—unless you think that COVID is worse than death.”
The study population mainly consisted of healthy adults, and the researchers noted that even mRNA vaccines were expected to reduce overall mortality in real-world scenarios. However, they added that the intriguing differences in the effects on non-accident, non-COVID-19 mortality were likely to persist and should be investigated further in future studies.
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