There are plenty of vaccines that use attenuated viruses - these also force your cells to produce antigens, and in fact the virus reproduces in your cells and damages them on its own as well. You could think of an mRNA vaccine as kind of like an attenuated virus vaccine, except for the fact that it can’t reproduce itself at all, unlike a virus.
JPLeRouzic's point about indiscriminate expression is significant though.
The tiny lipid bubbles used to introduce the (recent mRNA-)vaccines should introduce foreign nucleic acids (RNA,DNA) just on the basis of there being a cell membrane to merge into, whereas virions ('virus particles'), attenuated strain or not, would typically (always?) co-opt some receptor or other trans-membrane molecule, other than the membrane phospholipids, to aid their introduction of foreign nucleic acids.
In other words, the virions are at least somewhat restricted/targeted in what cell types they enter, and in many cases even the susceptible cells can in principle affect their level of susceptibility by regulating how much of those co-opted molecules are created, or allowed to be transported to the surface. (Innate immune response includes cells generally becoming more wary about how they transport materials and metabolize molecules we might describe as carrying information)
So it's a prefectly good description, in my opinion, that
> [for these] mRNA vaccines, all cells produce the antigen (the spike protein) so they are indiscriminately killed by T-cells.
although there are indeed aspects which are similar with live vaccines.
reply