The mRNA vaccine tells your cells to create the spike protein that was isolated from the original virus for about 48 hours at levels much lower than the virus i

The mRNA vaccine tells your cells to create the spike protein that was isolated from the original virus for about 48 hours at levels much lower than the virus itself. mRNA is used up by this process which is why your cells stop producing the spike protein and go back to their previous functions. Your immune system then attacks the spike protein and is better adapted to do this next time giving you better protection. The virus takes over your cells completely turning them into covid virus factories destroying them in the process the new viruses then continues until your immune system can stop this. During this time the amount of spike protein from the viruses are much higher by order of magnitude than with the mRNA vaccine along with the damage cause by the virus replicating itself. The spike protein is thought to have some adverse effects around heart issues, it is not well understood. However the risk is thought to be much higher from the virus than the vaccine due to shear volume of spike protein and the data seems to confirm this.