i’m super foggy on the details, but in a talk a few months before the shutdown the CSO from moderna said they add some sort of functional group to inhibit degradation. i believe it was more complicated than just “ligate something that endonucleases can’t bind” and there were interesting reasons why, but i bet this information is available somewhere since the slides were made for investors. again my memory is super unreliable but i was definitely wondering how they got around that before she addressed it