A research study linking a very rare side effect to the Covid-19 mRNA vaccines was withdrawn by researchers after making a major math error.
The Canadian study hit the headlines after suggesting there is a 1 in 1,000 risk of people developing myocarditis or inflammation of the heart after receiving the Moderna or Pfizer / BioNTech vaccines.
But the paper’s conclusions were wrong, and the calculation was flawed.
The numbers used by researchers at the Ottawa Heart Institute underestimated the amount of vaccines shipped in Ottawa over a two-month period, with the result being 25 times smaller than the actual number.
They had initially based their estimate on a total of 32,379 vaccine doses and 32 cases of myocarditis, when in reality more than 854,000 doses were administered between June 1 and July 31.
The results of the study were used by anti-vaccination websites and social media accounts in the UK, the United States and Canada.
The study was a pre-print, which means that it still had to be reviewed by independent experts and accepted for publication in a renowned scientific journal. During the pandemic, the need for scientific answers to the Covid-19 crisis and the effectiveness of the vaccine has resulted in pre-print studies being highlighted much earlier than normal.
Covid-19 infection can also cause myocarditis in younger people. A separate US research team showed that this happened at a rate of around 450 cases per million infections among 12 to 17 year olds during the first 12 months of the pandemic.
This compares with 77 cases of myocarditis for every million men between 12 and 17 years of age after an mRNA vaccine dose, which means Covid is a higher risk than the vaccine.
In a statement on MedRxiv’s pre-print server, the researchers said, “During the process of open peer review of MedRxiv, we quickly received a number of reports from reviewers who were concerned that there was an issue with our reported incidence of There was myocarditis after mRNA vaccination.
“Our reported incidence appeared to be grossly inflated by an incorrectly small denominator (ie number of doses administered over the study period). We checked the data available at Open Ottawa and found that there was indeed a large underestimation, with the actual number of doses given being more than 800,000 (much higher than stated in the publication).
“In order to avoid misleading colleagues as well as the public and the press, we, the authors, would like to unanimously withdraw this paper due to incorrect incidence data.
“We would like to thank the many reviewers who tried to contact us and point out our mistake. We apologize to anyone who was upset or worried by our report. “