This is not accurate. The mRNA vaccine is mostly localized to the muscle in which the vaccine was injected and the lymph nodes (https://www.sciencedirect.com/science/article/pii/S2211124720302928). The mRNA instructs local cells to produce a small amount of spike proteins which are released by the cells but again, remain local to the injection site and lymph nodes. The cell then destroys the mRNA after a short period of time. Spike proteins, even if they were able to translocate to organs, have shown no evidence to be harmful in and of themselves, and the amount that would reach any part of the body are negligible.

mRNA vaccines do not alter dna or cells, either, so there is no modification to a cell. It is simply an instruction that directs the cell how to produce the spike protein so that we can force the body to create anti-spike antibodies.

Also, mRNA technology has not been abandoned, it is a promising biotechnology that shows hope to lead the way in cancer treatment and prevention, as well as many other viruses.