The mRNA vaccine is injected into muscle tissue and since tissue is made up of cells, mRNA vaccine goes into the cells. The body immune system is distributed throughout the body in the cells of the body.Yes about muscle tissue being a good injection site.
But the point is that the vaccine injection doe not get into cells, and you do not want them to get into cells.
All you want is the immune cell nearby to recognized the antigen and attack it.
There is no way for mRNA to get into cells, you do not want them to get into cells, where the immune system could no longer find them,
And it would be incredibly dangerous to inject something into healthy cells that would make them grow corona spikes.
Nor is there anything you could get into cells that would make them grow corona spikes.
The mRNA process to make spike proteins does not and can not happen in your muscle tissue.
It happens in stem cells in factories, where they do gene splicing to produce bulk quantity spike proteins.
What is Human Body Tissue? - Definition, Types & Examples - Video & Lesson Transcript | Study.com.