Scientists uncover major safety concerns over mRNA vaccine technology

The findings question whether the widespread use of mRNA vaccines was justified during COVID-19 or, indeed, for future applications

A new peer-reviewed article in the Journal of Toxicology examines what scientists have learned about modified-mRNA (modRNA) technology following its first large-scale use during the COVID-19 pandemic (Toxicological Vulnerabilities and Emerging Safety Signals in Modified mRNA Vaccine Technology: A Narrative Review of the COVID-19 Experience).

The authors examined the journey of the modRNA technology starting with the manufacturing and testing stages. They then evaluated the real world effects from the subsequent roll-out to billions of people via COVID-19 vaccines. They were surprised that, 6 years later, many important questions still remain unresolved about how this technology behaves inside the body, how it is manufactured, and how potential safety signals are investigated.

Specifically, their analysis focuses on how the vaccines travel through the body, how long modRNA and the resulting spike proteins persist, and how reliably cellular machinery translates the modified genetic instructions. It also examines manufacturing changes between clinical trials and commercial production, alongside evidence of adverse events, including myocarditis. Although many people seem not to have suffered from their COVID-19 vaccination, the authors document multiple serious adverse events associated with this new approach to vaccination.

The authors argue that safety assessment must examine all the products - intended or otherwise - of the technology, including the modified RNA, its lipid nanoparticle delivery system, all proteins produced and their interactions within the body.

The implications extend beyond COVID-19. As modified mRNA technology moves into further medical applications, the paper calls for comprehensive preclinical testing, transparent reporting and long-term studies capable of identifying persistent effects and differences in individual susceptibility.

Lead author, Dr. Quinn, at the Center for Environmental Research and Earth Sciences (CERES), adds,

“We are shocked that anyone would contemplate moving forward with this modRNA technology until these basic problems have been addressed. Public confidence in established medical regulatory bodies cannot be restored until there is full and transparent acknowledgment of the extent and seriousness of the adverse events associated with this technology.”

The paper’s message is summed up by co-author, Dr. Steven J. Hatfill, Former Chief Medical Officer of the Administration for Strategic Preparedness and Response (Health and Human Services):

"In the over 5 years since the roll-out of the mRNA Covid-19 drugs, the mRNA platform remains inadequately tested and may continue to pose significant health risks across all patient demographics.  It is critical to understand that its technological promise must be challenged by rigorous safety and efficacy studies."

Read the paper: Journal of Toxicology

Published: 15 October 2026

Full Citation details:

Gerry A. Quinn, Philipp Bagus, Antonio Sánchez-Bayón, Ronan Connolly, Clare Craig, Paul Frijters, Steven J. Hatfill, Anton O’Connor, Daniel Santiago, Ricardo F. Savaris, Michaéla C. Schippers, Willie Soon, Demetrios A. Spandidos, Helmut Sterz, Aristidis M. Tsatsakis, Harald Walach (2026). “Toxicological Vulnerabilities and Emerging Safety Signals in Modified mRNA Vaccine Technology: A Narrative Review of the COVID-19 Experience”. Journal of Toxicology. 8202757. https://doi.org/10.1155/jt/8202757