BMJ Public Health retracted a study on excess mortality during the COVID-19 pandemic that appeared to suggest vaccination and other countermeasures as a possible explanation, following an investigation by the journal and the authors’ institution.
“This article is retracted by the journal for misinformation in the discussion regarding the possible causes of excess mortality, and because the limited nature of the original work by the authors was not sufficiently described,” the retraction notice stated.
In its investigation, Princess Máxima Center in the Netherlands found that the article “pays disproportionate attention to the possibility that COVID-19 containment measures and vaccination might have caused excess mortality,” the notice explained, adding that the paper didn’t actually investigate any of the causes of excess mortality.
The investigation also found that the study “misleadingly cited literature that supported its own arguments, but did not sufficiently discuss relevant literature that supported alternative interpretations,” according to the notice.
Corresponding author Saskia Mostert, MD, PhD, of the Princess Máxima Center, wasn’t available to cooperate with the institutional investigation. However, she replied to a BMJ Group query in October 2025 (after the institution shared a summary of its report with the BMJ Group in May 2025) and said she would be willing to make some changes to the paper.
Yet the journal felt the changes would be insufficient, and concluded that the “discussion of causes of mortality is imbalanced, lacks rigor, and includes misinformation.”
Mostert testified in June at a Senate Homeland Security and Governmental Affairs subcommittee hearing chaired by Sen. Ron Johnson (R-Wisc.), in which she said that “blind fury” followed publication of her report.
Her written testimony alleged that “psychological manipulation and fear propaganda” were used during the pandemic to influence public behavior, and that “censorship and suppression tactics” were used against doctors and scientists who questioned the “official COVID narrative.”
The retraction notice said that the institution raised concerns with the BMJ Group about “questionable behavior” by Mostert in June but did not specify what those concerns were.
Two of the co-authors, Gertjan Kaspers, MD, PhD, and Minke Huibers, MD, PhD, both of the Princess Máxima Center, agreed with the retraction but did not agree that the article contains misinformation.
A fourth author, Marcel Hoogland, who is listed as an independent researcher based in Amsterdam, was not part of the investigation because he was not affiliated with Princess Máxima Center.
Speaking on behalf of Hoogland, Mostert told the BMJ Group that they both disagree with the retraction.
The retraction notice also noted that the institutional investigation found “no evidence of malicious intent, fabrication or falsification of data, or plagiarism on the part of the individuals who were investigated.”
The paper, titled “Excess mortality across countries in the Western World since the COVID-19 pandemic: ‘Our World in Data’ estimates of January 2020 to December 2022,” was originally published in May 2024 and an expression of concern was added only a month later.
After the BMJ Group sent out a press release on the paper, and it was covered by several news outlets, researchers began sounding the alarm. A spokesperson for the BMJ Group previously told MedPage Today that the “quality and messaging issues of the research came to light through clinicians contacting BMJ Public Health.”
Gideon Meyerowitz-Katz, PhD, an epidemiologist at the University of Wollongong in Australia, wrote in a Substack post at the time that the paper relied heavily on an earlier study, which the authors “re-analyzed badly, and then published it as novel work.” It also only looked at the years 2020-2022, and in 2023 excess deaths began to fall off, despite similar vaccination rates, he noted.
Helen Macdonald, MD, publication ethics and content integrity editor at BMJ Group, noted in a press release announcing the retraction that the case was “complicated because of the multiple issues requiring investigation, some of which had been partly investigated by the institution, and involved unpicking how the research came to be conducted and presented as it was.”
Macdonald also noted that the Princess Máxima Center has not made its full report publicly available.
