A Taylor & Francis journal has retracted a widely-read paper linking cardiac-related mortality to COVID-19 vaccines after an unsuccessful legal attempt by the lead author to block the withdrawal. That author says he is considering further legal action against the publisher.
The article, “Risk of all-cause and cardiac-related mortality after vaccination against COVID-19: A meta-analysis of self-controlled case series studies,” drew swift criticism when it was published in Human Vaccines & Immunotherapeutics in August 2023. At the time, critics and sleuths were quick to challenge the data and methods used in the paper, which now has more than 143,000 views on the Taylor & Francis website and has been cited 15 times, including by two letters to the editor of the journal and a response from the authors, according to Clarivate’s Web of Science.
The retraction notice, posted online January 16, states the retraction resulted from concerns that arose about the methodology of the study and the integrity and availability of the data. The authors provided a full response to the queries; however, the publisher determined the validity of the findings remained in question, the notice states. It continues:
In addition, after publication, a major dataset that formed a central part of the evidence presented in the paper has been removed from public access by the issuing government authority; therefore, key portions of the published analysis are unverifiable using publicly available data.
As verifying the validity of published work is core to the integrity of the scholarly record, we are, therefore, retracting the article. The corresponding author listed in this publication has been informed. The Editor and Publisher confirm that there is no allegation of research misconduct on the part of the authors.
The publisher’s decision was informed by its editorial policies and COPE guidelines, the notice states.
The retraction follows a December 11 decision by a federal court in Arizona rejecting a request for a temporary restraining order against the publisher by lead author Greg J. Marchand. The author pursued the order to prevent Taylor & Francis “from causing irreparable harm” to his “professional reputation by improperly retracting his published and peer-reviewed research article in breach of the parties’ contract and T&F’s duties of care as a publisher,” according to his November 2025 complaint.
The U.S. District Court for the District of Arizona found Marchand was unlikely to succeed on the merits of his claim, and declined to “impose restraints on a publisher’s editorial discretion,” which the court said would violate the publisher’s First Amendment rights. The court decision was first reported by Eugene Volokh.
In a statement sent to Retraction Watch, Marchand said he and his team stand behind the paper’s findings as well as “the methods used, which were appropriate to the data and tools available at that time.” Marchand is a gynecologic surgeon and managing director of Marchand Institute for Minimally Invasive Surgery, a non-profit research corporation based in Mesa, Arizona.
As part of the meta-analysis, Marchand and his coauthors included data from The Ladapo report, an analysis by Florida Attorney General Joseph Ladapo, according to Marchand’s 33-page defense of the paper. The report, released in October 2022, addressed vaccine safety and led to guidance from Ladapo advising against COVID-19 vaccines for men aged 18 to 39 because of a purported higher risk of cardiac-related death.
Data from Ladapo’s report has since been removed from the Florida Department of Health’s servers, said Marchand, who noted that, in accordance with COPE guidelines, it’s “acceptable to retract a meta-analysis under these circumstances.” He wasn’t pleased, however, with the wording in the retraction notice, which he said gives the impression a COPE standards review was performed.
“There was no COPE-compliant query that took place, and no evidence of any invalid finding,” he said in the emailed statement. “All questions were answered to absolute resolution, and no further concerns were raised by the editors or outside reviewers.”
Marchand said he is considering legal action for libel for the publisher’s ambiguous wording, “which could portray authors and their considerable work on this paper in a negative light.”
A spokesperson for Taylor & Francis said the publisher had no comment beyond the details in the retraction notice. “The retraction decision was made and communicated to the authors before the legal action, and therefore the legal action did not affect the decision to retract,” they added.
The Marchand paper evaluated a self-controlled case series, a novel study design “uniquely equipped to ethically quantify the safety of vaccination,” according to the abstract. The authors say they found three such case series, totaling about 750,000 patients.
The researchers found no significant association of COVID-19 vaccination with all-cause mortality, but concluded there was an increased risk of cardiac-related mortality linked to the vaccine. A subgroup analysis purported to show “the male gender is significantly associated with an increased incidence of cardiac-related deaths.”
Other studies have shown that myocarditis is a rare but possible side effect of the vaccines. Vinay Prasad, director of the Food and Drug Administration’s Center for Biologics Evaluation and Research, recently called for stricter regulations of new vaccines after claiming that the COVID-19 vaccine was linked to the death of at least 10 children, according to a leaked memo reported by STAT.
Shortly after the Human Vaccines & Immunotherapeutics paper was published in 2023, critics and sleuths began poking holes in the research.
In an August 2023 letter to the editor, independent researcher Borja Somovilla Del Saz of Valencia, Spain, raised concerns that authors relied on data from the Ladapo paper, which was not a peer-reviewed study. In addition, “sensitivity analyses were lacking, undermining result robustness, particularly in gender-specific outcomes,” Del Saz wrote in his letter.
Another letter to the editor, this one by Tyler Black of the University of British Columbia in Vancouver, highlighted “significant methodological, important omissions … and errors in data extraction” in the article.
The paper also became the source of much discussion on X, where sleuth Gideon Meyerowitz-Katz wrote a lengthy thread about what he called a “clear error” with the meta-analysis. Meyerowitz-Katz, a research fellow at the University of Wollongong in Australia and a coauthor on Black’s letter, explained the authors used two types of meta-analyses for the two different models: a random-effects model, and a fixed-effects model.
A fixed-effects model assumes the studies are essentially identical, while a random-effects model assumes the studies are different, and the differences are distributed in somewhat random ways, he explained in the August 2023 post.
“To me, this is an obvious error,” Meyerowitz-Katz wrote. “The correct thing to do in this situation would be to report both the fixed and random-effects models, because their results conflict, and discuss which one would potentially be more important to consider.”
Instead, it appears the main finding rested on a single, “arbitrary decision” about which statistical model to use for each analysis, Meyerowitz-Katz wrote.
Similar concerns were raised by Taylor & Francis in emails sent to Marchand by Jade Boyd, journals portfolio manager for the publisher, according to correspondence seen by Retraction Watch. In an email dated March 14, 2024, Boyd told Marchand the publisher sent his article for “confidential post-publication review to an independent expert, as is common in cases like this.”
In subsequent email exchanges that went on for more than a year, Boyd questioned Marchand about various aspects of the research, including queries about hazard ratios, and the sensitivity analysis, according to the email communication provided by Marchand.
The email exchanges indicate Marchand and his coauthors were responsive to the publisher’s investigation – which the retraction notice affirmed – sharing additional information, answering questions, and at one point, sending a corrected manuscript with new figures requested by Taylor & Francis for a correction.
The corrected article never went forward however, and the back-and-forth stalled. On November 12, 2025, the publisher sent Marchand an email stating that some of the major concerns with the paper remained unaddressed and Taylor & Francis intended to publish a retraction notice, according to a timeline in Marchand’s legal complaint. He sued the publisher on November 24, 2025, alleging breach of contract by Taylor & Francis, among other claims. Marchand claimed the publisher’s acceptance and publication of the article, its policies, and the journal’s adherence to COPE guidelines formed a contract between the publisher and Marchand, and that retraction would breach the contract.
District Judge Diane J. Humetewa disagreed, writing that while the Court recognizes the importance of contract enforcement in commercial transactions, “here Marchand has failed to sufficiently identify the enforceable terms of any agreement between the parties.”
In their 33-page response, Marchand and his coauthors address the criticisms against the paper, including their characterization of the Ladapo report as “a peer-reviewed publication” and concerns with the fixed- and random-effect models.
The characterization of the Ladapo report was “thorough, transparent, and justified, prioritizing scientific merit over external controversies,” according to the defense. The authors also contend the handling of the fixed- and random- effects models was “transparent, consistent with our pre-specified criteria, and aligned with established guidelines.”
“The sensitivity analyses and re-analysis under random effects validate the stability of our findings, and the critique’s alleged overturning relies on disputed data adjustments rather than a flaw in our model application,” they said. “No substantive deviation occurred, and our conclusions remain supported.”
When reached by Retraction Watch, Meyerowitz-Katz said it’s “a good thing” the study was retracted. “It was a very poorly-done meta-analysis that differed significantly from its own pre-registration without any discussion of why,” he told us. “In addition, the entire finding – that COVID-19 vaccines may increase cardiac mortality – was predicated on a single, openly political paper…. Had the authors only considered high-quality, peer-reviewed studies, they would similarly have not found an effect.”
Marchand has authored other recent research purporting to show harms related to vaccines, including a research collaboration with Peter McCullough about a connection between RSVpreF vaccines and pregnancy and preterm birth. The Wellness Company, where McCullough is chief scientific officer, sells an “Ultimate Spike Detox” aimed at treating purported vaccine-induced spike proteins that linger in the body after vaccination for $89 per bottle.
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