Studies suggest a link between an incurable and fatal prion disease known as Creutzfeldt-Jakob Disease (CJD) and COVID-19 vaccines.

Researchers believe the prion region from the original Wuhan COVID-19 variant's spike protein was incorporated into mRNA vaccines and adenovirus vector vaccines — given to hundreds of millions of humans — and that it can cause a new type of rapidly progressing sporadic CJD.

According to Mayo Clinic, CJD is a degenerative brain disorder that leads to dementia and, ultimately, death.

Although the Omicron variant does not have a prion region on its spike protein, current COVID-19 vaccines still use the genetic material — including the prion region — of the parent Wuhan strain.

A French pre-print paper published in May on CJD and COVID-19 vaccination identified a new form of sporadic CJD that occurred within days of receiving a first or second dose of Pfizer or Moderna COVID-19 vaccines.

Researchers analyzed 26 cases of CJD and found the first symptoms appeared on average 11.38 days after injection with a COVID-19 vaccine.

Of the 26 cases, 20 had died by the time the study was published and six were still alive.