Vedhara, K, Llewelyn, M B, Fox, J D et al. · Journal of neuroimmunology · 1997 · DOI
Researchers gave some ME/CFS patients a live polio vaccine while others received a placebo, and followed them to see what happened. The good news is that the vaccine did not make ME/CFS symptoms worse. However, blood tests showed that ME/CFS patients had some differences in how their immune systems responded to the vaccine compared to healthy people, including differences in fighting off the virus and in certain immune cell counts.
This study addresses a practical clinical question for ME/CFS patients—whether standard vaccinations are safe—while providing early evidence that immune dysfunction in ME/CFS may affect how patients respond to live vaccines at the cellular level. Understanding these immune differences could inform vaccine selection and monitoring strategies for this population.
This study does not prove that live polio vaccines cause ME/CFS or trigger disease onset. The small sample size (14 CFS patients) limits generalizability, and the altered immune responses observed do not necessarily indicate clinical harm or contraindication. The study cannot establish whether the immune differences reflect a primary ME/CFS defect or are secondary consequences of the disease.
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
Vedhara, K, Llewelyn, M B, Fox, J D, Jones, M, Jones, R, Clements, G B, et al. (1997). Consequences of live poliovirus vaccine administration in chronic fatigue syndrome.. Journal of neuroimmunology. https://doi.org/10.1016/s0165-5728(97)00032-5
BibTeX
@article{mecfsatlas-vedhara-1997-consequences-live,
author = {Vedhara, K and Llewelyn, M B and Fox, J D and Jones, M and Jones, R and Clements, G B and Wang, E C and Smith, A P and Borysiewicz, L K},
title = {Consequences of live poliovirus vaccine administration in chronic fatigue syndrome.},
journal = {Journal of neuroimmunology},
year = {1997},
doi = {10.1016/s0165-5728(97)00032-5},
note = {PubMed: 9143253},
url = {https://www.mecfsatlas.com/evidence/vedhara-1997-consequences-live},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/vedhara-1997-consequences-live
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