RNA would get thrashed by your immune system if it isn't encapsulated by something: liposome deliver of therapeutic RNA is really next-generation tech, and the fact that the RNA does what it's supposed inside the your cells is no small feat either.

From the CDC "ingredients" for the BioNTech/Pfizer vaccine, along with cholesterol (which modulates the stability of lipid membranes), they report using this molecule, which would form a phospholipid bylayer, just like our own cells use: https://www.sigmaaldrich.com/catalog/product/avanti/850365P?...

Pfizer one does contain 4 kinds of lipids to encase the RNA. The encapsulation percentage is however unknown. https://www.technologyreview.com/2020/12/09/1013538/what-are...

They're both encased in lipids. Pfizer didn't have long term data on long-term storage at standard freezer temperatures, but has since confirmed their vaccine can be stored at similar conditions to Moderna.