Why would you design a vaccine that may cause serious neurologic symptoms that mimic those of the disease? / Cell Reports Medicine

This article from Yale authors supports the idea of homology between antigens in the brain and spike protein, thus autoimmune effects on the brain may be due to SARS-CoV-2 infection or to vaccination-induced Spike protein:

Divergent and self-reactive immune responses in the CNS of COVID-19 patients with neurological symptoms

https://www.cell.com/cell-reports-medicine/fulltext/S2666-3791(21)00116-6

Summary

COVID-19 patients frequently develop neurological symptoms, but the biological underpinnings of these phenomena are unknown. Through single cell RNA-seq and cytokine analyses of CSF and blood from COVID-19 patients with neurological symptoms, we find compartmentalized, CNS specific T cell activation and B cell responses. All COVID-19 cases had CSF anti-SARS-CoV-2 antibodies whose target epitopes diverged from serum antibodies. In an animal model, we find that intrathecal SARS-CoV-2 antibodies are found only during brain infection, and are not elicited by pulmonary infection. We produced CSF-derived monoclonal antibodies from a COVID-19 patient, and find that these mAbs target both anti-viral and anti-neural antigens—including one mAb that reacted to both spike protein and neural tissue. Overall, CSF IgG from 5/7 patients contains anti-neural reactivity. This immune survey reveals evidence of a compartmentalized immune response in the CNS of COVID-19 patients and suggests a role for autoimmunity in neurologic sequelae of COVID-19.