Quantification of residual plasmid DNA and SV40 promoter-enhancer sequences in Pfizer/BioNTech and Moderna modRNA COVID-19 vaccines from Ontario, Canada
Bibliographic record
Abstract
For some of the COVID-19 vaccines, the drug substances released to market were manufactured differently than those used in clinical trials. Manufacturing nucleoside-modified mRNA (modRNA) for commercial COVID-19 vaccines relies on RNA polymerase transcription of a plasmid DNA template. Previous studies identified high levels of plasmid DNA in vials of modRNA vaccines, suggesting that the removal of residual DNA template is problematic. Therefore, we quantified the DNA load in a limited number of Pfizer-BioNTech and Moderna COVID-19 modRNA vaccine vials using two independent methods. Total DNA and specific DNA targets were quantified by Qubit fluorometry and quantitative polymerase chain reaction (qPCR), respectively on 32 vials representing 16 unique vaccine lots. RNase A treatment was used to assess the impact of RNA crosstalk in DNA fluorometry. A preliminary assessment of DNA fragment length and DNase I sensitivity were also performed. Total DNA ranged 371–1,548 ng/dose and 1,130–6,280 ng/dose in Pfizer and Moderna products, respectively. Specific DNA of multiple plasmid DNA targets ranged 0.22–7.28 ng/dose for Pfizer, and 0.01–0.78 ng/dose for Moderna. The SV40 promoter-enhancer-ori (0.25–23.72 ng/dose) was only detected in Pfizer vials. Oxford Nanopore sequencing of one vial found mean and maximum DNA fragment lengths of 214 bp and 3.5 kb, respectively. These data demonstrate the presence of 1.23 × 108 to 1.60 × 1011 plasmid DNA fragments per dose encapsulated in lipid nanoparticles. Using fluorometry, total DNA in all vials tested exceeded the regulatory limit for residual DNA set by the US Food & Drug Administration (FDA) and the World Health Authorization (WHO) by 36–153-fold for Pfizer and 112–627-fold for Moderna after accounting for nonspecific binding to modRNA. When tested by qPCR, all Moderna vials were within the regulatory limit, but 2/6 Pfizer lots (3 vials) exceeded the regulatory limit for the SV40 promoter-enhancer-ori by 2-fold. The presence of the SV40 promoter-enhancer element in Pfizer vials raises significant safety concerns. This study emphasizes the importance of methodological considerations when quantifying residual plasmid DNA in modRNA products, considering increased LNP transfection efficiency, and cumulative dosing presents significant and unquantified risks to human health.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".