Well believe it or not, this is how viruses and bacteria work. Your cell is a dumb protein factory. It gets factory orders from the DNA in your nucleus in the form of mRNA. Your cell just synthesizes whatever protein the RNA specifies. So when a microbe like an RNA virus get in to the cell it just spills its RNA guts and your stupid cell starts making new baby viruses. That’s why viruses love you. You are a big dumb protein factory. The RNA vax isn’t too far off from this but it gets the RNA from a lipid envelope that enters the cell and melts or dissolves or whatever. Then the protein factory starts making just the spike protein, which can’t replicate and that is all your T cells need to see to build antibodies. Now this is going to blow your mind. Viruses and bacteria develop camoflage (molecular mimicry) to look like certain proteins in your body naturally. This helps them evade the immune system a little while while they reproduce. But when the immune system eventually starts building antibodies to kill the invaders, it sometimes makes a mistake and the antibodies start killing your own body tissue in a case of mistaken identity. This is autoimmunity. Its the cause of lupus and MS and rheumatoid arthritis and hypothyroidism and type 1 diabetes and dozens of other diseases. Every time you get infected and have an immune reaction you could get an autoimmune disease. Naturally the same thing can happen with the vaccine. Any vaccine.