A vial of Pfizer-BioNTech Covid-19 vaccine is seen at a pop up vaccine clinic in the Arleta neighborhood of Los Angeles, California, August 23, 2021 ( AFP / Robyn Beck)

Physical therapist misleadingly ties Covid vaccine to thyroid problems

  • Published on March 19, 2024 at 19:40
  • 3 min read
  • By AFP USA
A physical therapist suggests in an Instagram post viewed thousands of times that Covid-19 vaccines may exacerbate thyroid problems. But the study cited fails to show a causal relationship -- and the authors say rare side effects should not deter vaccination, which public health agencies worldwide recommend.

"This is how the Covid vaccine can actually be worsening your thyroid condition, especially if you're a woman," says Austin Lake in a clip posted March 11, 2024.

The physical therapist adds that if someone "recently noticed more weight gain or fatigue after getting the vaccine, this may be connected."

Screenshot of an Instagram post taken March 18, 2024

The claim is the latest in a wave of misinformation about Covid-19 vaccines, which researchers estimate have saved millions of lives.

Lake cites a 2023 study titled "Insights into new-onset autoimmune diseases after Covid-19 vaccination" (archived here). The paper, published in the peer-reviewed journal Autoimmunity Reviews, focuses on the shot's potential links to rare autoimmune diseases. 

While the study says the vaccines "may cause rare autoimmune diseases," it also notes "a causal relationship between Covid-19 vaccination and these autoimmune phenomena needs to be further explored."

The authors also say the benefits of inoculation "far outweigh the possible risks." Public health authorities say coronavirus vaccination is safe and effective at preventing severe illness and death (archived here and here).

"What the speaker doesn't mention at all is that while there may be active investigation into whether Covid-19 vaccination is associated with new onset autoimmune conditions, there is strong evidence that Covid-19 infection is associated with new onset autoimmune conditions," said Devon Greyson, a public health researcher at the University of British Columbia (archived here), on March 15.

AFP contacted the authors of the study for comment, but a response was not forthcoming.

'No significant increase'

To support his claim, Lake references other scientific studies -- but two were published prior to the pandemic.

One 2015 paper (archived here) focuses on disparities in symptoms of hypothyroidism, a deficiency of hormones produced by the thyroid gland (archived here), between different genders. Another published in 1988 (archived here) looks at hypothyroidism tied to autoimmune causes.

Meanwhile, the American Thyroid Association said in January 2023 that it had found no evidence of an increase in thyroid problems among Covid-19 vaccinated patients (archived here).

"In this largest vaccinated group analysis to date, there was no significant increase in the incidence of thyroid problems in the 56 days after Covid-19 vaccination by either the inactivated virus or by mRNA," the professional group said.

The Centers for Disease Control and Prevention (CDC) told AFP on March 15, 2024 that "authorized and approved Covid-19 vaccines have been administered under the most comprehensive and intensive vaccine safety monitoring effort in US history." 

"Extensive research and safety monitoring has not established an association between Covid-19 vaccination and thyroid disease or any autoimmune diseases with one exception: evidence of an increased risk of Guillain-Barré Syndrome (GBS) was found among adults after receipt of the Janssen Covid-19 vaccine, which is no longer available for use in the United States," the agency said.

Tara Kirk Sell, an associate professor at the Johns Hopkins Bloomberg School of Public Health (archived here), told AFP that "study after study has shown that, while there are small risks that can be associated with vaccination against Covid-19, these are much smaller than risks from the disease itself."

She added that "leveraging existing fears and concerns is a common tactic" to spread disinformation about Covid-19.

"In this case, cancer, heart disease and autoimmune disease affect large segments of the population, so this rumor will have a lot of salience with many people and leverage that towards virality," Sell said March 14.

AFP has fact-checked other false and misleading claims about Covid-19 here.

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