This sort of mRNA work isn’t immune-driven at all, in theory, and if you need your target cells to keep producing your desired protein, you’re going to have to

This sort of mRNA work isn’t immune-driven at all, in theory, and if you need your target cells to keep producing your desired protein, you’re going to have to keep telling them that by sending them more mRNA. Once a day? Once a week? Who knows? That’ll need to be worked out by experiment. This doesn't seem like a problem from the point of view of those who are in the business of selling mRNA :)