Marius it's not quite like a live virus. A live virus has a DNA or RNA 'message' encoding all its proteins inside a virion, a particle designed to protect the message. Whereas the mRNA product is yes, a message to the cells which take it up, enclosed in an artificial vesicle called LNP (lipid nano particle). One difference is that the mRNA product doesn't as far as I know encode instructions for packaging and releasing the mRNA message. But something similar may be happening with exosomes, which are extracellular vesicles, which might be used by the cell to dispose of the spike proteins built in accordance with the mRNA instruction supplied in the jab; it appears those exosome+spike are causing an antibody response. Another key difference here is that the exosome+spike is not self reproducing -- it is not a packaged message with instructions to make more spike. So although there concerns that I think are legitimate about the effects fof shedding, it's not quite the same as a live virus infection in those two ways. I don't think anyone has found any evidence for the mRNA being shed from the body, the concerns I have heard of are more about where in the body it is accumulating, whether it ever breaks down, and what the longer term effects are on the body.