The 187 days seems right by my personal experience following an autoimmune reaction after the 2nd initial Pfizer dose (never did take any boosters after that and because of that).
I'm afraid that the "187 days" is just an artifact of the study, which ended after that period of time. That is, it only marks the time when they stopped looking. If the hypothesis that the mRNA reverse transcribes into a vaccinee's DNA were to prove true, then that would suggest that that person's cells might never stop producing spike protein.
This, in turn, would provide an explanation for the IgG4 immune dysfunction that is beginning to emerge.
A lot of "ifs," yes, but that's why studies are now ongoing. Studies that should have been conducted before this garbage vaccine was "warp-speeded" onto a gullible public.