The Infodemiology Brief —

False claims about COVID-19 vaccines and heart damage

Welcome to the Health Care Infodemiology Brief, a newsletter for clinicians and other health care providers.

Concerns about COVID-19 vaccine safety continue to cause vaccine hesitancy, fueled by a constant stream of misleading and false claims from vaccine opponents, including some prominent political officials. These anti-vaccine narratives are not original: They’re old claims given new life when attached to misrepresented studies, misused data, and political posturing.

For even more resources, check out the menu above for real-time insights, training resources, and more. Specifically curated for doctors and other health care providers, these links provide actionable content to help navigate today’s information landscape.

Trending narratives from the past month


Studies misrepresented to falsely claim that vaccines cause heart damage
A frequent misleading claim about COVID-19 vaccines—and a persistent source of vaccine hesitancy—is that they cause heart damage. Anti-vaccine narratives often misrepresent or misinterpret the findings of legitimate studies. In one recent example, vaccine opponents claimed that two studies that found trace amounts of inactive vaccine mRNA in heart tissue prove that mRNA vaccines cause heart damage, a claim that one of the studies’ authors disputed. Other studies that found rare instances of mild, temporary changes in heart tissue after COVID-19 vaccination have been misrepresented to claim that the vaccines cause long-term or permanent heart damage. In each example, vaccine opponents mischaracterize and even contradict the studies’ conclusions. Read the fact checks here and here.


Vaccine opponents misuse health data to falsely link COVID-19 vaccines to excess deaths
COVID-19 vaccines have saved millions of lives since their rollout in late 2020. Worldwide, higher vaccination rates correspond to lower excess mortality. Yet, vaccine opponents continue to promote the false narrative that COVID-19 vaccines increased excess deaths, often misusing and manipulating official mortality data. Non-peer reviewed “analyses” attempt to baselessly link millions of deaths to COVID-19 vaccines. A recent extreme example of mortality data misuse involved a New Zealand health worker who was arrested for allegedly accessing and distributing private health data to a prominent COVID-19 vaccine opponent, who falsely claimed that the data showed that COVID-19 vaccines caused 13 million deaths worldwide. Read the fact checks here and here.


US officials ramp up anti-vaccine tactics
Several U.S. officials are using their platforms to promote false information about COVID-19 vaccines. A member of Congress hosted a congressional hearing about alleged “vaccine injuries,” featuring anti-vaccine physicians who falsely claimed that COVID-19 vaccines cause pregnancy complications and infertility. At the state level, the Texas attorney general recently announced a lawsuit against Pfizer, claiming that the company "unlawfully misrepresented” the effectiveness of its COVID-19 vaccine. The lawsuit cites Pfizer’s clinical trial data showing 95 percent efficacy as “misleading” and falsely claims more vaccinated people are dying from COVID-19 based on cherry-picked U.K. data from four weeks in late 2021 and early 2022. Read the fact checks here and here.

What you might say in response

Worried about your heart? Get vaccinated. You’re more likely to have heart issues after a COVID-19 infection than after vaccination.

  • COVID-19 vaccination is not associated with an increased risk of cardiac events—COVID-19 infection is. In fact, COVID-19 vaccination may decrease the risk of heart attack, stroke, and other cardiovascular issues in people who have had COVID-19.
  • Contrary to claims by vaccine opponents, none of their cited studies found evidence of permanent heart damage. The referenced studies were either not in humans or detected mild, transient heart tissue inflammation or scarring but no signs of heart damage or impaired heart function.
  • Billions of people worldwide have received COVID-19 vaccines, with only extremely rare instances of myocarditis, or heart inflammation, being reported. Research consistently shows the rarity of post-vaccination heart complications and that COVID-19 infection carries a higher risk of heart complications than COVID-19 vaccination, even in higher-risk groups like teenage boys and young men.

Data from billions of vaccinated people show that COVID-19 vaccines save lives.

  • With over two-thirds of the world’s population vaccinated, studies show that COVID-19 vaccination is not linked to increased mortality.
  • Claims that COVID-19 vaccines killed millions are based on the false assumption that excess deaths after the COVID-19 vaccine rollout must be related to the vaccines. In reality, excess deaths closely correspond with spikes in COVID-19 infections, not COVID-19 vaccination rates.

Over three years of research prove the safety and effectiveness of COVID-19 vaccines.

  • Two-thirds of the world’s population—over 5 billion people—received the primary COVID-19 vaccine series, with no evidence of widespread health issues.
  • Over three years of research and rigorous safety monitoring worldwide have proven repeatedly that COVID-19 vaccines are safe for all eligible populations, including those who are pregnant or planning to become pregnant.
  • The claims in the recent congressional hearing and Texas lawsuit are largely based on low-quality studies and misinterpretations of unverified vaccine safety data.
  • Data from Texas and the rest of the country show that since the vaccine rollout, unvaccinated people are far more likely than vaccinated people to die from COVID-19.

What we’re reading

Studies and trainings


Interested in learning more about how to debunk false claims with patients? Check out the new Infodemiology Training Program. In videos that range from 5 to 10 minutes each, the program introduces health care providers to the basics of infodemiology and provides you with actionable skills to help improve patient care. Get started today.

Quick response media assets

Below, we’ve provided a social media asset in English and Spanish. These assets can be used on social media to fight false claims and help provide your network with accurate information. Just right-click the asset, or press and hold on mobile, to download.

Proposed social copy:
Even a mild COVID-19 infection can cause lasting heart damage and increase your risk of serious heart issues like heart attacks. Fortunately, COVID-19 vaccination helps protect against the dangers of COVID-19 by reducing the risk of heart complications. Research shows that vaccine-related heart issues are extremely rare and that COVID-19 infection causes a far higher risk of heart complications than vaccination. Take care of your heart by getting vaccinated against COVID-19.

Publicación propuesta:
Incluso una infección leve de COVID-19 puede causar daño cardíaco duradero e incrementar su riesgo de problemas cardíacos serios como infartos de miocardio. Afortunadamente, las vacunas contra el COVID-19 ayudan a protegerlo contra los peligros del COVID-19 al reducir los riesgos de complicaciones cardíacas. Las investigaciones demuestran que los problemas cardíacos relacionados a las vacunas son extremadamente raros y que la infección con COVID-19 causa un riesgo mucho mayor de complicaciones cardíacas que vacunarse. Cuide su corazón poniéndose la vacuna contra el COVID-19.

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