Fehrer, Annick, Sotzny, Franziska, Kim, Laura et al. · Journal of clinical medicine · 2025 · DOI
Researchers tested whether a piece of the COVID-19 virus (spike protein) lingering in the blood after infection could explain ME/CFS symptoms. They found spike protein in some patients' blood months after COVID, but it was present in similar amounts in people who recovered well and those with ME/CFS. This suggests that leftover spike protein is probably not the main cause of ME/CFS.
Understanding whether persistent viral proteins drive ME/CFS is crucial for identifying treatment targets and explaining disease mechanisms in post-COVID patients. This study provides evidence that spike protein alone does not explain ME/CFS development, potentially redirecting research toward other mechanisms such as immune dysregulation, viral persistence in other tissues, or autonomic dysfunction.
This study does not prove that spike protein plays no role in any post-COVID symptoms—only that it is not associated with ME/CFS specifically. It also does not establish causation and cannot rule out spike protein involvement in other tissues or other post-COVID conditions. The small number of spike protein-positive samples limits statistical power to detect associations if they exist.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Fehrer, Annick, Sotzny, Franziska, Kim, Laura, Kedor, Claudia, Freitag, Helma, Heindrich, Cornelia, et al. (2025). Serum Spike Protein Persistence Post COVID Is Not Associated with ME/CFS.. Journal of clinical medicine. https://doi.org/10.3390/jcm14041086
BibTeX
@article{mecfsatlas-fehrer-2025-serum-spike,
author = {Fehrer, Annick and Sotzny, Franziska and Kim, Laura and Kedor, Claudia and Freitag, Helma and Heindrich, Cornelia and Grabowski, Patricia and Babel, Nina and Scheibenbogen, Carmen and Wittke, Kirsten},
title = {Serum Spike Protein Persistence Post COVID Is Not Associated with ME/CFS.},
journal = {Journal of clinical medicine},
year = {2025},
doi = {10.3390/jcm14041086},
note = {PubMed: 40004616},
url = {https://www.mecfsatlas.com/evidence/fehrer-2025-serum-spike},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/fehrer-2025-serum-spike
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