People often ask why is a simple DNaseI reaction failing for Pfizer? What other artifacts are present in this manufacturing process?
Sutton et al is a good place to start. Even in 1997 they knew DNA:RNA hybrids were treated very differently by DNaseI. The Pfizer vaccine is a DNA:modRNA hybrid and is in even more uncharted water.
Basically, when they use T7 RNA polymerase to copy RNA off of a DNA template, the resulting product is a DNA:RNA hybrid. A triple helix that DNaseI doesn’t recognize.