The negative effectiveness needs to be explored further. I've begun to think of the mRNA therapies as a kind of "steroid". In the case of human growth hormone (HGH), one course will certainly help you generate muscle growth in the short term, particularly if you're trying to rehab an injury quickly; but repeated abuse has less-the-zero deleterious effects on the body, up to and including Leukemia. I suspect that continued boosting will be deleterious to at least one's immune system, but probably a number of other systems as well. You are, after all, forcing massive numbers of cells in the body to do something they were never intended to do. Like, well, Leukemia...