Assessment of Residual Plasmid DNA and SV40 Promoter-Enhancer Elements in modRNA-Based COVID-19 Vaccines from Pfizer-BioNTech and Moderna Sourced in Ontario, Canada

David J. Speicher and colleagues. Autoimmunity. 2025 Dec;58(1):2551517. doi: 10.1080/08916934.2025.2551517. Epub 2025 Sep 6. Abstract In the development of certain COVID-19 vaccines, variations occurred between the manufacturing processes for drug substances intended for market release and those employed during clinical evaluations. The production of nucleoside-modified messenger RNA (modRNA) for these commercial vaccines involves in vitro…