Plasmid DNA Contamination in mRNA Vaccines: Theoretical Mechanisms of Integration, Latency, Episome Formation, and Oncogenic Transformation

The rapid development of mRNA-based COVID-19 vaccines has raised concerns about potential risks associated with plasmid DNA contamination during vaccine production. Plasmids used in these vaccines contain regulatory elements, like SV40 promoters, antibiotic resistance genes, and sequences for mRNA expression. These plasmids are often linearized during production and not entirely removed. When introduced into human cells via lipid nanoparticles (LNPs), these plasmids may undergo degradation, integration, or random concatemerization. This process, mediated by the host cell's DNA repair machinery, can result in plasmid DNA either integrating into the host genome, persisting as dormant plasmids, or forming latent plasmids. Each of these fates carries distinct oncogenic risks: integrated plasmids may directly contribute to genomic instability, while dormant or latent plasmids can remain quiescent within the nucleus but potentially reactivate under certain conditions, driving oncogenic transformation. This work hypothesizes that these processes could bypass the multi-hit theory of cancer by accelerating cellular transformation, potentially inducing stem-like characteristics in differentiated cells like macrophages and endothelial cells. The activation of transcription factors like SP1 by SV40 promoters, ion channel dysregulation via volume-regulated anion channels (VRAC), and the cGAS-STING pathway, which senses DNA and modulates immune responses, may further enhance the risk of oncogenesis. This paper highlights the importance of understanding potential mechanisms, urging the need for improved quality control in RNA vaccine production to mitigate the potential oncogenic risks posed by plasmid DNA contamination.