https://www.salk.edu/news-release/the-novel-coronavirus-spik...
Derek Lowe has a post that discusses this.
In short from what I remember, the vaccine is administered in the deltoid, so most of the spike proteins should remain there. Some may travel throughout the body, but overall it is much much less than a natural infection.
That’s why I’m curious to compare myocarditis rates after vaccination to those after infection, because from what we know, natural infection should result in a higher rate of myocarditis than vaccination.
If the problem is inflammation then that seems entirely plausible... I thought that an immune response was exactly what inflammation is
I don't think we have the data either way to be sure the spike protein is completely harmless, though obviously how dangerous it is is bounded by the fact that many people experience no ill effects. (That is, it obviously can't be super-ultra-deadly, because it's not killing everyone instantly. How dangerous it could possibly be is bounded by the fact that many people have received the vaccine.)