BNT162b2 mRNA COVID vaccine causes cells to express proteins other than the S1 spike protein (as if that wasn’t bad enough) as antigens for your immune system to then target and develop antibodies against.
Which proteins? That’s anyone’s guess.
https://phmpt.org/wp-content/uploads/2023/02/125742_S1_M4_4.2.1-r-20-0211.pdf