The Infodemiology Brief —

How vaccine opponents misuse scientific research

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

The safety of COVID-19 vaccines has been well-established over the last three years. But that hasn’t stopped vaccine opponents from seizing every opportunity to advance the narrative that the vaccines are harmful or even deadly. Misrepresenting the results of legitimate studies is a common tactic to dispute vaccine safety. Vaccine opponents also frequently exploit big news stories and manufacture misleading “data leak” stories to keep false narratives in the headlines.

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


Misrepresentation of preliminary studies stoke COVID-19 vaccine safety fears
Preliminary studies are an important part of vaccine safety research, but they can also be used to promote misleading narratives. Vaccine opponents often misinterpret or intentionally misrepresent the results or significance of these studies to give a false impression that COVID-19 vaccines are unsafe. In a recent example, an FDA preprint study flagged seizures as a potential safety signal for COVID-19 vaccines in young children. The analysis explained that the finding should be interpreted cautiously due to the study’s limitations, a warning ignored by many social media users. Another recent FDA study in older adults found a potential risk of a slight increase in stroke following the high-dose flu shot, whether alone or in combination with a bivalent COVID-19 vaccine. However, the study found no risk associated with the COVID-19 vaccine alone. Misleading headlines and social media posts gave the false impression that the study linked COVID-19 vaccines to elevated stroke risk. Read the fact checks here and here.


Conspiracies claim COVID-19 vaccine myocarditis risk was covered up
Conspiracies that health authorities and vaccine manufacturers misled the public about COVID-19 vaccine risks are common online, often accompanying misleading document “leaks.” Several conspiracy news sites published emails that allegedly reveal that Pfizer and Moderna executives and members of the Biden administration covered up COVID-19 vaccine risks, including myocarditis and blood clots. In reality, the emails didn’t reveal any previously unknown or damning information but showed that federal authorities promptly alerted the public to potential rare vaccine risks. Screenshots of a Pfizer press release also went viral in recent weeks as vaccine opponents claimed it’s the first time the company has “admitted” that myocarditis was a potential COVID-19 vaccine risk. This is untrue, as similar messaging about myocarditis has appeared in Pfizer materials related to COVID-19 vaccines since mid-2021. Read the fact checks here and here.

Vaccine opponents use current events to amplify messages
Social media users who promote anti-vaccine rhetoric often latch onto current events and major news stories to find new audiences and expand the reach of their message. This trend continued in October as vaccine opponents seized on the conflict in Israel and Gaza to advance anti-vaccine talking points. In viral posts that reached millions, some accounts baselessly claimed that COVID-19 vaccine-related deaths far outnumber the deaths in the conflict and questioned why alleged vaccine injuries haven’t received as much news coverage. Similar false claims circulated in response to the Russia-Ukraine conflict and various natural disasters such as the Maui wildfires and Turkey-Syria earthquakes. Read the fact check here.

What to say in response

Our country’s vaccine safety monitoring systems are working.

  • Preliminary and non-peer reviewed research cannot be used to draw conclusions about COVID-19 vaccine safety.
  • There is no evidence that COVID-19 vaccines increase stroke risk in any age group. The data showing a potential seizure risk in young children is preliminary, and further analysis suggests it may represent a false risk.
  • Researchers investigate all potential safety signals to ensure that vaccines are as safe as possible. The detection of extremely rare safety signals is a sign that vaccine safety monitoring systems are working as they should.
  • Experts, including both studies’ authors, continue to encourage COVID-19 vaccination for those who are eligible.

Infections like COVID-19 are the most common cause of myocarditis.

  • Federal health authorities were the first to alert the public to myocarditis as a potential risk of mRNA COVID-19 vaccines shortly after detecting the safety signal.
  • There is considerable evidence from two years of research that myocarditis after COVID-19 vaccination is extremely rare, typically mild, and often resolves on its own.
  • Infections like COVID-19 are the most common cause of myocarditis. You are much more likely to have myocarditis after a COVID-19 infection than you are after vaccination.


Billions of people have been vaccinated against COVID-19. The vaccines are safe.

  • Social media posts often exploit tragic and widely covered news stories to spread anti-vaccine messages.
  • There is strong evidence showing that COVID-19 vaccines are not linked to widespread health issues or deaths.
  • In fact, vaccine clinical trials, three years of safety monitoring, and real-world data clearly demonstrate the safety of the mRNA vaccines.

What we’re reading

Annenberg Public Policy Center: Vaccine Confidence Falls as Belief in Health Misinformation Grows
USA Today: Anti-science rhetoric heavily funded, well-organized. Can it be stopped?
CIDRAP: Global COVID vaccination saved 2.4 million lives in first 8 months, study estimates
The LA Times: Column: Why anti-vaxxers are pretending a flawed study on vaccine deaths has been vindicated
Your Local Epidemiologist: Fall 2023 vaccine coverage and reaching “passive positives”

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 click on the share button, and it will pop up in a new window. Then right-click the asset to download.

Proposed caption copy:
Wondering how to highlight to immunocompromised patients the importance of staying up to date with COVID-19 vaccines? Check out this video with some of the more common questions about updated COVID-19 vaccines this season.

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