Pfizer and Moderna’s COVID-19 vaccines, which are based on messenger RNA (mRNA) technology, do not affect overall mortality, according to a reanalysis of clinical trial data.
The researchers, including Christine Stabell Benn, professor of health at the University of Southern Denmark, published their findings in the journal Cell in April. The study found that while mRNA vaccines protected against deaths related to COVID-19, vaccinated participants were more likely to die from cardiovascular problems.
“In RCTs with the longest blinded follow-up possible, mRNA vaccines had no effect on overall mortality despite protecting against some deaths from COVID-19. On the other hand, adenovirus vector vaccines were associated with lower overall mortality,” the researchers said.
“Differences in the effects of adenovirus vector and mRNA vaccines on overall mortality, if true, would have an important impact on global health,” they later added.
Benn and colleagues extracted data from three RCTs for mRNA vaccines and six RCTs for adenovirus vector vaccines, all of which had mortality data available. They compared the number of deaths between the vaccinated group and the placebo group, classifying them as related to COVID-19, due to cardiovascular problems, caused by other factors other than COVID-19, accidents and non-accidental causes, not COVID -19. .
The research involved analyzing data from randomized clinical trials (RCTs) conducted by 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 mortality from COVID-19, but an increase in cardiovascular and non-accidental, non-COVID-19 mortality. However, there was no difference in overall mortality between the vaccinated group and the placebo group.
For the Johnson & Johnson vaccine, it was associated with lower overall mortality and non-COVID-19 mortality, with no effect on COVID-19 mortality. AstraZeneca’s vaccine, which was not licensed in the United States but approved in some other countries, performed well for overall mortality and in several categories in several trials, except for one trial in which slightly more vaccinated individuals died for non-Covid or non-accidental causes. , causes not COVID-19.
The researchers stated that adenovirus vector vaccines, compared to placebos, appeared to have non-specific beneficial effects, reducing the risk of non-COVID-19 diseases. Cardiovascular disease was identified as the most important non-COVID-19 cause of death, and data from current RCTs suggested that adenovirus vector vaccines provided at least some protection against it.
The study was published in 2022, before peer review, but had difficulty finding a journal that would accept it for publication. Benn stated that several journals rejected the article without giving an explanation, leading to delays in publication.
After the launch of vaccines, including in highly vaccinated countries such as the United States, there was an increase in global mortality. The causes of this increase are still debated among researchers, with some attributing it primarily to vaccines and others citing COVID-19 and other factors.
Dr Peter Gotzsche, emeritus professor and director of the Danish Institute for Scientific Freedom, praised the paper, calling it “thought-provoking”.
Dr. David Boulware, a professor of medicine at the University of Minnesota Medical School, expressed concern about the new study’s methodology. In an email to The Epoch Times, he claimed the study was poorly designed because of variations in the sites where the trials took place. Boulware argued that countries with better health care, 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 study populations in the RCTs of the two types of vaccines could have biased the comparison, as different disease patterns and level of care could have influenced the measured effect of vaccines on overall mortality.”
In addition, the researchers noted that in the mRNA clinical trials, more individuals became infected with COVID-19 compared to the adenovirus vector vaccine trials, but there were more deaths from COVID-19 in the adenovirus vector assays. This suggests that participants in the mRNA trials may have had access to better health care during COVID-19 infection, which could have affected the measured effect of mRNA vaccination on overall mortality.
Boulware also pointed to real-world data, including observational data from Israel and Minnesota, that he believes contradict the paper’s conclusions. He stated that mRNA vaccines clearly offer better protection against COVID-19 compared to adenovirus vector vaccines.
In response, Benn defended the study, noting that it was based on a meta-analysis of randomized placebo-controlled clinical trials, which is considered the highest level of evidence. Data from randomized clinical trials are considered the “gold standard” for medical research. The main goal of the study, according to Benn, was overall mortality.
“It’s talking about COVID-19; we’re looking at all-cause mortality,” Benn said. “It is irrelevant if one vaccine protects better against COVID-19 than another if it reduces overall mortality to a lesser degree, unless you think that COVID is worse than death.”
The study population consisted mostly of healthy adults, and the researchers noted that mRNA vaccines were even expected to reduce overall mortality in real-world scenarios. However, they added that intriguing differences in effects on non-accidental and non-COVID-19 mortality are likely to persist and should be further investigated in future studies.
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