No, the major difference in the Pfizer and Moderna vaccines are in the makeup of the lipid nanoparticle. Here's an article from Moderna last year on biodegradability of the LNPs they've developed. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6383180/
Thanks for this article. I can see both vaccines consider the use of PEG to be important. Still looking for the other lipid ingredients in the Moderna vaccine.