Results: … we found preliminary evidence of a dose response relationship of the amount of DNA per dose and the frequency of serious adverse events (SAEs). This relationship was different for the Pfizer and Moderna products. Size distribution analysis found mean and maximum DNA fragment lengths of 214 base pairs (bp) and 3.5 kb, respectively. The plasmid DNA is likely inside the LNPs and is protected from nucleases. Conclusion: These data demonstrate the presence of billions to hundreds of billions of DNA molecules per dose in these vaccines. Using fluorometry, all vaccines exceed the guidelines for residual DNA set by FDA and WHO of 10 ng/dose by 188 – 509-fold…
It's the Center for Open Science which runs a number of pre-print sites, including one on their own site where this paper was posted.
With such a serious issue, I'll wait to see what emerges from the other end of the peer review process.