Blood markers and vascular function testing for people with persistent symptoms after COVID-19 vaccination
Clinical Laboratory Evaluation, Assessment of Symptoms and Recovery in Patients With Post-COVID-19-Vaccination Syndrome
This project will test blood tests and a finger-based vascular scan (EndoPAT) in adults who developed long-lasting symptoms after a COVID-19 vaccine to see how symptoms and biological signs change over time.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 200 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | University of Bern Academic / other |
| Locations | 1 site (Bern) |
| Trial ID | NCT07400848 on ClinicalTrials.gov |
What this trial studies
This observational effort follows adults with self-reported persistent symptoms after COVID-19 vaccination and matched healthy controls to map symptom trajectories and biological measures. Participants provide blood samples for analysis of coagulation, endothelial, and inflammatory markers and undergo non-invasive EndoPAT testing to measure reactive hyperemia index. The PROGRESS arm includes an eight-month follow-up while ENDOCLOT and REAL include more detailed laboratory and matched-control comparisons. Results will be used to link biological signatures to symptom patterns and recovery over time.
Who should consider this trial
Good fit: Ideal participants are adults (≥18) who speak German, report new persistent symptoms that began after a COVID-19 vaccination, and are willing to provide blood samples and attend in-person vascular testing and follow-up.
Not a fit: People with active cancer, current immunosuppression, known pregnancy, severe cognitive or physical impairment, or symptoms clearly unrelated to vaccination are less likely to benefit and may be excluded.
Why it matters
Potential benefit: If successful, the project could identify measurable blood or vascular markers that help diagnose PACVS and point toward targeted treatments.
How similar studies have performed: Related work in post-COVID and ME/CFS populations has reported mixed but suggestive findings for endothelial dysfunction and coagulation markers, so this approach is plausible but not yet proven for PACVS.
Eligibility criteria
Show full inclusion / exclusion criteria
General Criteria (apply to all study parts: PROGRESS, ENDOCLOT, REAL, patients and matched healthy controls) Inclusion Criteria 1. Age ≥ 18 years 2. Sufficient knowledge of German to complete study-related questionnaires and procedures Exclusion Criteria 1. Severe cognitive, physical impairment or psychiatric conditions impeding participation 2. Active oncological disease or immunosuppressive 3. Known pregnancy at the time of enrolment PROGRESS (patients only) Inclusion Criteria 1. Coded participation with online consent confirmation 2. Self-reported onset of persistent symptoms temporally associated with a COVID-19 vaccination 3. Willingness and ability to participate in the 8-month follow-up period Exclusion Criteria 1\. No specific exclusion criteria for this part ENDOCLOT and REAL (patients and matched healthy controls) Inclusion Criteria 1. Signed informed consent form 2. For patients: 1. Receipt of at least one COVID-19 vaccination 2. Onset of new, otherwise unexplained symptoms within 0-14 days after vaccination 3. Persistence of symptoms for at least 6 months following vaccination 4. Selection is based on a diagnosis of ME/CFS according to the Canadian Consensus Criteria (CCC) and PEM. 2\. For controls: History of COVID-19 vaccination without persistent adverse effects; age (+/- 10 years), and sex match to a corresponding case Exclusion Criteria (patients and matched healthy controls) 1. Clinically suspected or laboratory confirmed SARS-CoV-2 infection after vaccination or temporally related to symptom onset. 2. Concurrent pre-existing Long COVID symptoms, obtained from the patient´s history 3. Any self-reported or uncertain history of an acute infectious event (including mild or subclinical infections) in temporal proximity to COVID-19 vaccination 4. Known pre-existing medical conditions or ongoing medications that could plausibly explain the reported symptoms (e.g., preexisting ME/CFS, POTS, fibromyalgia, small-fiberneuropathy, autoimmune disease with systemic involvement or other chronic multisystemic dysautonomia syndromes) 5. Use of long-term, high-dose anti-inflammatory
Where this trial is running
Bern
- Institute of Sport Science, University of Bern — Bern, Switzerland (Recruiting)
Study contacts
- Principal investigator: Mirko Schmidt, Prof. Dr. — Institute of Sport Science, University of Bern, Switzerland
- Study coordinator: Mirko Schmidt, Prof. Dr.
- Email: CLEAR.ispw@unibe.ch
- Phone: +41 79 342 67 30
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.