"SARS-CoV-2 spike RNA- and SARS-CoV-2-related inflammation persist in the epipharynx for more than six months post infection. Although no expression of the SARS-CoV-2 spike protein in the epipharynx was evident in these patients with long COVID, genetic analysis revealed activation of [...] the SARS-CoV-2 signalling pathway in epithelial cells, B cells, and pDCs. This aligns with theories that even nonactive viral fragments may possess biological significance. This persistence of inflammation, identified for the first time at the genetic level, highlights the epipharynx as a critical site for continual immune responses in long COVID patients, suggesting that residual viral antigens may contribute to the chronic symptoms experienced"
"After the administration of EAT [epipharyngeal abrasive therapy] once a week for 3 months, the expression of viral RNA disappeared in patients 1 and 2. Patient 3 presented a substantial reduction in viral RNA expression; although complete clearance was not achieved, a marked decrease was observed."
"observed dysregulation of immune and ciliary pathways" - might explain the chronic nonsmoker cough that seems more common now
"These findings suggest that T cells still play a subtle role in the immune dysregulation observed in patients with long COVID. Collectively, these findings indicate that interactions among pDCs, B cells, plasma cells, and T cells contribute to the chronic inflammation and immune dysregulation characteristic of patients with long COVID"
"In the pre-EAT state of long COVID Patient 2, the tissue surface was predominantly covered by ciliated epithelium (Cluster 7). In contrast, following treatment, the ciliated epithelium was no longer observed, and a new cluster of squamous epithelial cells (Cluster 12) emerged"
"EAT effectively eliminates the inflamed ciliated epithelium in patients with long COVID and induces the formation of squamous cells with high barrier function"
https://www.nature.com/articles/s41598-025-92908-7
thanks @MEActNOW
