Viral Persistence Drives Long Covid Pathology

SARS-CoV-2 RNA and proteins persist in multiple tissues months after acute infection. Studies document reservoirs in gut, lung and brain samples from patients with ongoing symptoms. Primary evidence comes from PCR and immunohistochemistry assays in postmortem and biopsy tissues. Autoantibodies targeting neural and vascular proteins appear at elevated rates in Long Covid cohorts versus controls. Flow cytometry and ELISA data link these antibodies to microvascular and neurological complaints. Mitochondrial gene expression changes measured by RNA-seq correlate with fatigue severity scores. T-cell exhaustion markers including PD-1 and TIM-3 remain upregulated in peripheral blood of affected individuals. Single-cell sequencing from two independent cohorts shows sustained interferon signaling signatures absent in recovered controls.