In the case of POIS symptoms being driven by (auto)antibodies. I wonder if the example below, from ME/CFS patient (Maj-Britt), works for some cases of POIS. Injecting blood into a chicken, which in turn would induce IgY antibodies against the POIS autoantibodies and consume the eggs.
https://en.wikipedia.org/wiki/Immunoglobulin_Y
"Immunoglobulin Y (abbreviated as IgY) is a type of immunoglobulin which is the major antibody in bird, reptile, and lungfish blood. It is also found in high concentrations in chicken egg yolk."
IgY: A promising antibody for use in immunodiagnostic and in immunotherapy
https://forums.phoenixrising.me/threads/list-of-me-cfs-recovery-and-improvement-stories.80502/
Consuming IgY Immunoglobulins From Chicken Eggs
"ME/CFS patient (Maj-Britt) a Swedish women cured her Chlamydia pneumoniae-associated ME/CFS with a simple home treatment consisting of orally consuming IgY antibodies from a chicken egg yolk. She injected the chicken with her blood, so the chicken started making antibodies against the infections in her blood. Those chicken antibodies are naturally produced in large quantities in the eggs the chicken lays."