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Baseless claim that COVID-19 vaccines killed more than 200,000 comes from flawed BMC Infectious Diseases study

Posted on:  2023-02-03

Key takeaway

Despite claims made on social media, a study published by the peer-reviewed journal BMC Infectious Diseases doesn’t actually provide the necessary scientific evidence for its claim that nearly 300,000 people died from COVID-19 vaccines. This estimate is based on a survey of about 2,800 people, but doesn’t involve verifying the accuracy of survey responses by examining medical records. As such, the study doesn’t offer a reliable estimate of deaths related to the COVID-19 vaccines.

Reviewed content


More than 200,000 people may have died due to the COVID-19 vaccine

Source: BMC Infectious Diseases, Mark Skidmore, 2023-01-24

Verdict detail

Conflates factual statement and opinion: The claim is based on a survey that asked people whether they thought someone they knew had died from the COVID-19 vaccines, and then treated these personal opinions as facts. This isn’t a rigorous or reliable method to establish the cause of death.

Full Claim

“With these survey data, the total number of fatalities due to COVID-19 inoculation may be as high as 278,000”; “New peer-reviewed study: >217,000 Americans killed by the COVID vaccines in just the first year alone!”; “Covid Vaccines Killed 278,000 Americans by the end of 2021, Peer Reviewed Study Finds”


Claims that a “peer-reviewed study” found that the COVID-19 vaccines killed hundreds of thousands of people went viral at the end of January 2023. The claim is based on a study published in the journal BMC Infectious Diseases, authored by economist Mark Skidmore who is a professor at Michigan State University. [Editor’s note: The study has since been retracted. The full retraction notice can be read here. After the retraction, Skidmore’s analysis was published in Science, Public Health Policy, and the Law with some modifications.]

The study made the rounds on Twitter, thanks to shares by individuals who’ve expressed vaccine skepticism with large followings, such as cardiologist Aseem Malhotra, entrepreneur Steve Kirsch, and podcaster Daniel Horowitz. To date, the study has been tweeted more than 15,000 times, based on its Altmetric statistics.

Briefly, the study conducted an online survey of American citizens to ask whether they or people they knew experienced health problems after COVID-19 or after COVID-19 vaccination, and whether these experiences influenced their decision to get vaccinated. A total of 2,840 people completed the survey. According to the study, the survey population was representative of the American population.

Skidmore reported that people who knew someone who’d had a health problem after COVID-19 were more likely to get vaccinated. By contrast, those who knew someone who’d experienced a health problem after vaccination—regardless of whether vaccination was known to be the cause— were less likely to get vaccinated. Political orientation also played a role: Democrats were generally more likely to get vaccinated compared to Republicans, consistent with the partisan gap also detected by a survey from the Kaiser Family Foundation and a working paper by the National Bureau of Economic Research.

The study begins to run into problems when it tries to estimate “COVID-19 vaccine fatalities”, claiming that “Estimates from the survey indicate that through the first year of the COVID-19 vaccination program there may be as many as 278,000 vaccine induced fatalities”.

Establishing how many people died from a particular cause using survey responses that are essentially personal opinion is neither rigorous nor reliable. As scientists and physicians pointed out, determining the cause of a person’s death requires a review of their medical records and death certificates, which wasn’t done in the study. To date, the U.S. Centers for Disease Control and Prevention (CDC) recognizes only nine deaths as due to the COVID-19 vaccines, specifically the Janssen vaccine.

The study also made some unjustified assumptions about the risks of heart attacks, strokes, and blood clots, claiming that “The average age of a person in the survey dataset who experienced these conditions after being vaccinated is about 40 years of age, and the average age of death is 48. The incidence of heart attacks (myocardial infarction) for people of age 48 is about 17 per 100,000, and the incidence of strokes and blood clots for this age group is very low, near zero”. 

The only citation for this claim is the CDC WONDER database for underlying cause of death, which allows users to search for mortality data. However, this data only tells us about the number of people who died from a particular disease, which is a subset of the people who developed the disease, not all of them. So it’s unclear how the CDC WONDER database would be able to tell us the incidence of a disease.

In any event, epidemiological studies don’t support Skidmore’s assumption of “near zero” incidence for strokes and blood clots at the average age given. The incidence of stroke in U.S. adults aged 20 to 44 was estimated at 28 per 100,000 people in 2015[1], and the risk of stroke increases with age. The incidence of venous thromboembolism, one of the most common blood clotting disorders, was estimated at around 30 per 100,000 people in those aged 25 to 40[2]

The results of the Framingham Heart Study, a long-term study launched in 1948 that is now in its third generation, also place the incidence of heart attacks for people in their forties at a higher level than Skidmore’s figure of 12. In a study published in 2009, the annual incidence of heart attacks for people aged 40 to 49 ranged between 20 to 45 per 10,000 person-years, depending on the decade studied[3].

Overall, the study appears to downplay the baseline risks of heart attack, stroke and blood clots. At the same time, it implies that the risks associated with COVID-19 vaccination are higher by describing heart attacks, strokes, and blood clots as “three commonly reported vaccine adverse events”. In fact, the most commonly observed COVID-19 vaccine adverse events are fever, headache, and pain at the injection site.

Although the study claimed to use a sample representative of the U.S. population, scientist Susan Oliver pointed out in a YouTube video that only 51% of the survey participants reported being vaccinated (this data is available in Table 2 of the study), when during the time the survey was conducted (between 18 and 23 December 2021), the vaccine coverage in the U.S. population was well above that figure, as numbers by the CDC show. This bias in the study population may translate to bias in the responses. Skidmore’s representation of the study as “based on a sample that closely matches the US population” doesn’t hold up under scrutiny.

Figure 1. Vaccine coverage in male and female populations around the time that the survey was conducted. Both the proportion of people who received at least one dose (top) and those who completed the vaccination series (bottom) are well above the vaccine coverage reported in Skidmore’s study (about 51%). Data retrieved on 3 February 2023. Source: CDC COVID Data Tracker.

Cardiologist Frank Han also highlighted in a tweet that the source Skidmore cited to support the claim that Dynata sampling provides “high quality data” and “community norms of honesty and accuracy” doesn’t actually provide information on this, being a study about public attitudes on post-traumatic stress disorder. Health Feedback didn’t find any mention of Dynata in the study.

Skidmore declared no conflict of interest, but also stated that the study was funded by Catherine Austin Fitts. Fitts was assistant secretary of housing and urban development for housing during the presidency of George H. W. Bush, and is presently president of Solari Inc. She has made inaccurate claims about COVID-19 and vaccines and has spoken at a conference held by the anti-vaccine organization Children’s Health Defense.

Skidmore’s personal blog Lighthouse Economics also pushes the narrative that COVID-19 vaccines are unsafe (see examples here, here, and here). Overall, whether there is actually no conflict of interest, as Skidmore declared, is a matter of debate.

On 26 January 2023, the journal added an Editor’s Note to Skidmore’s article, stating that:

“Readers are alerted that the conclusions of this paper are subject to criticisms that are being considered by editors. Specifically, that the claims are unsubstantiated and that there are questions about the quality of the peer review. A further editorial response will follow the resolution of these issues.”

In response to Health Feedback’s request for comment, the editorial office of BMC Infectious Diseases stated in an email that “We are aware of the issues raised on this publication. An editorial note of concern has been published regarding this article on the 26th of January. We cannot comment on ongoing investigations.”

We also reached out to Skidmore and Michigan State University’s Institutional Review Board, which approved Skidmore’s study, for comment and will update this review if new information becomes available.

On 11 April 2023, BMC Infectious Diseases retracted the study following an investigation. Among the issues it found were the use of inappropriate metholodogy and inadequate description of the study’s methodology. The journal also noted that contrary to Skidmore’s declaration, the study was exempt from ethics approval and wasn’t actually approved by the IRB of the Michigan State University Human Research Protection Program.

After its retraction from BMC Infectious Diseases, Skidmore’s analysis was published in Science, Public Health Policy, and the Law in October 2023. The editorial board of this publication includes several individuals known to be opposed to vaccination, including bioinformatician James Lyons-Weiler, pediatrician Paul Thomas, and chemical engineer Brian Hooker.

While some parts of the analysis have been modified (this article points out some of the modifications), its central argument—that asking people why they think someone died post-vaccination is a valid and accurate way to estimate vaccine-related deaths—still remains.

In October 2023, posts began appearing, reviving this claim. These posts also alleged that Skidmore was “exonerated” by the MSU IRB, implying this meant his analysis was methodologically sound.

But this is a misrepresentation of the IRB’s conclusions. The IRB is in charge of ensuring that research on human subjects is conducted in an ethical manner. It had investigated a complaint that Skidmore had been “noncompliant” with research protocols, but ultimately found “no noncompliance”.

This conclusion however, has no bearing on the validity of the methods used by Skidmore, which remain unsound. As such, the claim that Skidmore’s analysis provides evidence for more than 200,000 vaccine-related deaths is baseless. Health Feedback has debunked numerous claims that COVID-19 vaccines are responsible for excess deaths here, here, and here.


Overall, this study doesn’t actually provide the necessary scientific evidence for its claim that nearly 300,000 people died from COVID-19 vaccines. This estimate is based on personal opinions, with no attempt at verifying the accuracy of survey responses by examining medical records. Unsurprisingly, the study doesn’t offer a rigorously tested or reliable estimate of deaths related to the COVID-19 vaccines.

UPDATE (27 October 2023):

After its retraction from BMC Infectious Diseases, Skidmore’s analysis was published in October 2023 in Science, Public Health Policy, and the Law, with some modifications. However, it still preserves its central incorrect argument—that asking people why they think someone died post-vaccination is a valid and accurate way to estimate vaccine-related deaths. We added this information in the twenty-first to the twenty-fifth paragraphs. We also noted the ruling of the Michigan State University’s IRB finding “no evidence of noncompliance” in Skidmore’s research, and also how this has been misrepresented as a validation of Skidmore’s findings.

UPDATE (17 April 2023):

Skidmore’s study was retracted on 11 April 2023, following an investigation by the journal. We updated the first paragraph in the review to signal the retraction and added a new paragraph detailing some of the journal’s findings to the conclusion at the end of the review. The full retraction notice can be read here.

CORRECTION (6 February 2023):

The graph on vaccine coverage for fully vaccinated people was missing from the initial publication. The graph has now been added to Figure 1.


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