Yet another study indicates the brain is negatively affected by Covid, yet we're still okay with children getting it repeatedly.
Our new study shows that SARS-CoV-2 spike protein accumulates and persists in the body for years after infection, especially in the skull-meninges-brain axis, potentially driving long COVID. mRNA vaccines help but cannot stop it. Summary: We found SARS-CoV-2 spike protein in the skull-meninges-brain axis in mouse models and human post-mortem tissues long after their COVID, which was associated with vascular, inflammatory changes in the brain along with neuronal damage. Approach: To discover all tissues that are targeted by SARS-CoV-2, we used unbiased DISCO clearing technology and mapped tissues hit by coronavirus spike vs. Influenza HA proteins (flu).Main Findings1: Along with many organs, we discovered spike accumulations in the skull marrow niches and recently discovered skull-meninges connections (SMCs), revealing a new route of pathogens into the brain.2: Critically, we found the spike protein also in the skull bone marrow niches, and meninges of people who died from COVID-19.3: Although COVID-19 patients' brain tissue was PCR-negative, spike protein was present in the brain, suggesting a longer half-life compared to viral particles.4: Using unbiased proteomics, we found several dysregulated proteins involved in the neurodegeneration, coagulation cascades, neutrophil degranulation, and the PI3K-AKT signaling in the skull marrow, meninges, and brain of COVID-19 patients.5: SARS-CoV-2 spike S1 protein i.v. injection alone was enough to trigger a wide range of proteomic changes in the skull marrow, meninges, and brain compared to the HA protein. These changes are similar to those observed in virus-infected human samples.6: Furthermore, injection of spike protein directly into skull marrow resulted in acute and long-term neuronal injury in mouse brain cortex tissue (observed as cell death and increased APP expression), while influenza HA did not lead to any changes.7: Strikingly, we found spike accumulation in ~60% of people who had COVID-19 in the past long after their recovery. Thus, the identified spike in the human skull beyond the viral detection time might be a co-factor in developing long-term COVID-19 symptoms.8: Compared to the control group, patients with Long COVID showed significantly elevated levels of neurodegenerative disease-related proteins, such as Tau protein and neurofilament light chain (NfL), in their cerebrospinal fluid.9: The immune response triggered by the spike protein may activate the MAPK-JNK signaling pathway, leading to neuronal stress and inflammation.10: In stroke and traumatic brain injury mouse models, the presence of spike protein exacerbates brain tissue damage, suggesting that it may enhance the susceptibility of the nervous system to further insults.11: The accumulation of spike protein in mice vaccinated with the BioNTech/Pfizer vaccine was significantly reduced, but not completely eliminated. This suggests that vaccination can significantly reduce the long-term effects of the virus on the nervous system, providing important support for reducing the risk of sequelae of COVID-19.Clinical implications and future research directions• Diagnosis: Neural injury markers in cerebrospinal fluid may be used as an important indicator for evaluating the sequelae of COVID-19.• Treatment: In the future, strategies for the removal or inhibition of spike proteins may become an important way of treating the sequelae of COVID-19.This study on the skull-meninges-brain axis and the persistence of spike proteins offers novel insights into the neural injury mechanism underlying COVID-19 sequelae. Future research should delve deeper into the mechanisms of spike protein entry and retention in brain tissue, as well as potential variations among different COVID-19 variants. Such investigations may pave the way for accurate diagnosis and personalized treatment of COVID-19 neurological sequelae.