Ward, Daniel, Thorsen, Nicklas Myrthue, Frisch, Morten et al. · Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin · 2019 · DOI
This study examined adverse event reports submitted to Danish health authorities after HPV vaccination between 2009 and 2017. Researchers found that fatigue, dizziness, and headache were common symptoms reported, and noticed that some clusters of reports—particularly those mentioning cognitive problems and sleep issues—were submitted during periods of increased media coverage about vaccine safety concerns.
For ME/CFS patients, this study is relevant because it documents reports of fatigue and cognitive dysfunction following HPV vaccination in a large population. Understanding whether these symptoms represent true vaccine adverse events or reporting artifacts influenced by media coverage has implications for vaccine safety pharmacovigilance and patient experiences of post-vaccination illness.
This study does not establish whether HPV vaccination actually causes CFS, POTS, or CRPS, as it only analyzes reported adverse events without control groups or comparison to background incidence rates. The temporal clustering of reports during media activity suggests reporting bias rather than biological causation. The study cannot determine if reported symptoms constitute true diagnoses or represent misattribution of unrelated conditions.
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
Ward, Daniel, Thorsen, Nicklas Myrthue, Frisch, Morten, Valentiner-Branth, Palle, Mølbak, Kåre, & Hviid, Anders (2019). A cluster analysis of serious adverse event reports after human papillomavirus (HPV) vaccination in Danish girls and young women, September 2009 to August 2017.. Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin. https://doi.org/10.2807/1560-7917.ES.2019.24.19.1800380
BibTeX
@article{mecfsatlas-ward-2019-cluster-analysis,
author = {Ward, Daniel and Thorsen, Nicklas Myrthue and Frisch, Morten and Valentiner-Branth, Palle and Mølbak, Kåre and Hviid, Anders},
title = {A cluster analysis of serious adverse event reports after human papillomavirus (HPV) vaccination in Danish girls and young women, September 2009 to August 2017.},
journal = {Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin},
year = {2019},
doi = {10.2807/1560-7917.ES.2019.24.19.1800380},
note = {PubMed: 31088598},
url = {https://www.mecfsatlas.com/evidence/ward-2019-cluster-analysis},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/ward-2019-cluster-analysis
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