There’s absolutely no risk of harm to the person. I don’t even know how there could be, since all you’re doing is going into a factory…
You have an incomplete view of the process and the risks. I’ll explain how there can be harmful side effects:
As the RNA vaccine takes command of the cellular protein factory, it diverts cellular resources (ribosome and amino acids) needed by the cell. Resources used for manufacturing the viral protein are not available to manufacture native proteins, and the cell is less able to perform its normal life functions.
The cell generates foreign (viral) proteins that are not only useless to the cell, but get in the way of normal cellular operations. For example, viral spike proteins transported to the cell membrane will take up space in the membrane and interfere with native membrane proteins.
If these diverting and interfering effects alone do not kill the cell, the immune response surely will. Antibodies and T-cells produced in response to the vaccine will seek out and kill any cells bearing the viral proteins.
So, at a minimum, the cells involved in the RNA-directed production will die. They are sacrificed. This is no worse than what happens with the live virus. It’s better actually, because the RNA vaccine is not self-replicating like the virus. But a few cells are necessarily killed in the process. (By few, I mean millions, which is a small fraction of the billions of cells in the human body.)
I do not know which cell types are taken over by the RNA vaccine. If they are muscle cells or another type which is easily replaced, I would not be too worried. But what if the RNA vaccine has a high affinity for cells in a vital organ? That organ would become inflamed and compromised. This possibility worries me.
Finally there is concern over the immune response itself. If the vaccine triggers a prolonged inflammatory response in some individuals, or an auto-immune response, that can be life-changing and life-threatening.
I applaud your wish to encourage people to take the vaccine, but in so doing, you must not gloss over real and significant risks.