A preprint study finding that the Pfizer-BioNTech mRNA COVID vaccine is associated with an increased risk for cardiac adverse events in teenage boys has elicited a firestorm on Twitter. Although some people issued thoughtful critiques, others lobbed insults against the authors, and still others accused them of either being antivaccine or stoking the fires of the vaccine skeptic movement.
The controversy began soon after the study was posted online September 8 on medRxiv. The authors conclude that for boys, the risk for a cardiac adverse event or hospitalization after the second dose of the Pfizer mRNA vaccine was “considerably higher” than the 120-day risk for hospitalization for COVID-19, “even at times of peak disease prevalence.” This was especially true for those aged 12 to 15 years and even those with no underlying health conditions.
The conclusion – as well as the paper’s source, the Vaccine Adverse Event Reporting System (VAERS), and its methodology, modeled after the Centers for Disease Control and Prevention assessment of the database – did not sit well with many.
“Your methodology hugely overestimates risk, which many commentators who are specialists in the field have highlighted,” tweeted Deepti Gurdasani, senior lecturer in epidemiology at Queen Mary University of London. “Why make this claim when you must know it’s wrong?”
“The authors don’t know what they are doing and they are following their own ideology,” tweeted Boback Ziaeian, MD, PhD, assistant professor of medicine at the University of California, Los Angeles, in the cardiology division. Dr. Ziaeian also tweeted, “I believe the CDC is doing honest work and not dredging slop like you are.”
“Holy shit. Truly terrible methods in that paper,” tweeted Michael Mina, MD, PhD, an epidemiologist and immunologist at the Harvard School of Public Health, Boston, more bluntly.
Some pointed out that VAERS is often used by vaccine skeptics to spread misinformation. “‘Dumpster diving’ describes studies using #VAERS by authors (almost always antivaxxers) who don’t understand its limitations,” tweeted David Gorski, MD, PhD, the editor of Science-Based Medicine, who says in his Twitter bio that he “exposes quackery.”
Added Dr. Gorski: “Doctors fell into this trap with their study suggesting #CovidVaccine is more dangerous to children than #COVID19.”
Dr. Gorski said he did not think that the authors were antivaccine. But, he tweeted, “I’d argue that at least one of the authors (Stevenson) is grossly unqualified to analyze the data. Mandrola? Marginal. The other two *might* be qualified in public health/epi, but they clearly either had no clue about #VAERS limitations or didn’t take them seriously enough.”
Two of the authors, John Mandrola, MD, a cardiac electrophysiologist who is also a columnist for Medscape, and Tracy Beth Hoeg, MD, PhD, an epidemiologist and sports medicine specialist, told this news organization that their estimates are not definitive, owing to the nature of the VAERS database.
“I want to emphasize that our signal is hypothesis-generating,” said Dr. Mandrola. “There’s obviously more research that needs to be done.”
“I don’t think it should be used to establish a for-certain rate,” said Dr. Hoeg, about the study. “It’s not a perfect way of establishing what the rate of cardiac adverse events was, but it gives you an estimate, and generally with VAERS, it’s a significant underestimate.”
Both Dr. Hoeg and Dr. Mandrola said their analysis showed enough of a signal that it warranted a rush to publish. “We felt that it was super time-sensitive,” Dr. Mandrola said.