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Why are mRNA vaccines an unlikely cause of any neurodegenerative diseases?

This article was published on
April 29, 2021

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April 30, 2021: The U.S. Department of Health and Human Services updated the Vaccine Adverse Event Reporting System (VAERS) database on April 30, 2021. While there is still no evidence indicating that COVID-19 vaccinations can cause prion-related diseases, the VAERS database now reports a very small number of relevant cases (ex. Alzheimer's type dementia, multiple sclerosis, neurological symptoms). The number of reported cases for these symptoms were mostly in the single digits (occasionally in the teens), out of over 100 million people in the U.S. who received at least one vaccine dose, so it is incredibly rare for neurological issues to be reported after COVID-19 vaccination. Patients may experience symptoms due to a variety of reasons, including underlying health conditions, so VAERS reports do not necessarily mean that symptoms were caused by vaccination or that a link to vaccination has been confirmed. Additionally, VAERS relies on reporting from vaccine providers and provides the disclaimer that "reports may include incomplete, inaccurate, coincidental and unverified information." Research to develop safe mRNA vaccines has been happening for decades before the COVID-19 pandemic, and experts agree that mRNA vaccines remain highly safe and effective for the vast majority of people. At this time, there is no scientific evidence to suggest that prior-related disorders could be caused by mRNA vaccination.

There is currently no scientific evidence that the COVID-19 mRNA vaccines by Pfizer or Moderna lead to neurodegenerative diseases.

There is currently no scientific evidence that the COVID-19 mRNA vaccines by Pfizer or Moderna lead to neurodegenerative diseases.

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What our experts say

Neurological impacts from COVID-19 infections are now documented in multiple peer-reviewed scientific studies. However, there is currently no scientific evidence that the COVID-19 mRNA vaccines lead to neurodegenerative diseases. Unvaccinated individuals are at higher risk of serious illness from COVID-19 infection, which can cause temporary as well as longer-term neurological impacts in some patients.

In order to receive emergency use authorization in the U.S., the approved mRNA vaccines went through rigorous clinical trials and scientific review. Regulators found serious adverse reactions to be exceedingly rare. Pfizer and Moderna clinical trials included tens of thousands of participants and have not found links between vaccination and neurodegenerative diseases.

A spokesperson for the U.S. Centers for Disease Control and Prevention (CDC) said that the national monitoring body, VAERS (Vaccine Adverse Event Reporting System), had "no reports of prion-related diseases, Alzheimer's disease, or amyotrophic lateral sclerosis (ALS) after COVID-19 vaccination." There is "no evidence to date" for claiming a "causative association between COVID-19 vaccines and these conditions," the spokesperson said.

Vaccines are widely considered highly safe and effective for the vast majority of adults to protect themselves from COVID-19.

False claims link COVID-19 mRNA vaccines to neurodegenerative diseases, and many reference work by anti-vaccinationist J. Bart Classen. Before the COVID-19 pandemic, Classen wrote about the Hib (Haemophilus influenzae type b), making claims based on limited evidencethat have been disputed by other researchers.

On January 18, 2021, a three-page paper by Classen entitled "COVID-19 RNA Based Vaccines and the Risk of Prion Disease" was accepted for publication in Microbiology & Infectious Diseases. Unlike typical scientific papers, this paper by Classen does not include a clear description of methods, nor does it refer to any data for analysis in the results section. The paper inconsistently refers to prion disease, Alzheimer's disease, amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), and other types of neurodegeneration throughout the text. The second paragraph of the discussion section says "prion disease including Alzheimer’s disease, ALS..." despite Alzheimer's disease and ALS being categorized differently than prion diseases.

The conclusion of the paper advances unproven conspiracy theories about the COVID-19 pandemic being caused by bioweapons, despite experts at the World Health Organization and other research institutions concluding that laboratories are "unlikely" to be the origin of COVID-19. Additionally, it is unclear if this paper was peer-reviewed by qualified experts in the field, since the publisher of Microbiology & Infectious Diseases was identified as a predatory open-access publisher on Beall's List.

This paper and the claims referencing it were flagged as suspicious by the online misinformation tracking firm VineSight, and debunked through fact-checking from organizations like The Poynter Institute.

Context and background

There is currently no scientific evidence that the COVID-19 mRNA vaccines by Pfizer or Moderna lead to neurodegenerative diseases. In order to receive emergency use authorization in the U.S., the approved mRNA vaccines have gone through rigorous clinical trials and scientific review, which found serious adverse reactions to be exceedingly rare.

Resources

  1. The coronavirus vaccine doesn’t cause Alzheimer’s, ALS (PolitiFact)
  2. Prion disease (U.S. Centers for Disease Control and Prevention)
  3. Prion disease (University of California San Francisco)
  4. Origins of the SARS-CoV-2 virus (World Health Organization)
  5. List of Potential Predatory Journals and Publishers (Beall's List)
  6. Selected Adverse Events Reported after COVID-19 Vaccination (U.S. Centers for Disease Control and Prevention)
  7. How COVID-19 attacks the brain (American Psychological Association)
  8. How COVID-19 can damage the brain (Nature)

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