Suppose a valid administration of an mRNA vaccine (e.g. Pfizer / Moderna), lipid nanoparticles with the mRNA instructions enter the cell, the lipid particles will merge with the endosome and the mRNA will release to the cytoplasm (do not enter the nucleus) before finding a ribosome.
How long will any of this stay in the cell? Is it a once off and after the production of the spike protein the mRNA evaporates from the cell? and what about the lipid nanoparticles?