Many have asked me how to differentiate (=DD) between longCovid and longVax(PVS).
Below I’ll try to give you, although lengthy, sorry, a simplified overview, with some references, to follow, but caution, we can dig even deeper!😉
It’s not a flow-chart, it’s an attempt to guide you in the DD.
Important remark first, longVax exists, yes, but is very rare, certainly today, but for the patient it can be hell.
Many longVax patients can actually be longCovid patients, a far larger group( >>millions!), post-C19!
Even Overlaps exist between the two but these are extremely rare!
Enjoy the read……but sit down first! 1/N
Below I’ll try to give you, although lengthy, sorry, a simplified overview, with some references, to follow, but caution, we can dig even deeper!😉
It’s not a flow-chart, it’s an attempt to guide you in the DD.
Important remark first, longVax exists, yes, but is very rare, certainly today, but for the patient it can be hell.
Many longVax patients can actually be longCovid patients, a far larger group( >>millions!), post-C19!
Even Overlaps exist between the two but these are extremely rare!
Enjoy the read……but sit down first! 1/N
A detailed history is of the utmost importance:
1.Timing of Onset:
-Long COVID symptoms typically emerge or persist 4-12 weeks post-infection resolution, with gradual evolution and a duration ≥2-3 months-years.
-PVS often has acute onset within hours to days post-vaccination (e.g., 1-7 days for initial fatigue/brain fog), progressing to chronicity in <1% of cases, with shorter latency to severe manifestations.
sciencedirect.com/science/articl…
2.Symptom Profiles:
-Core overlaps include fatigue (58-70%), headache (44%), cognitive impairment/brain fog (27-40%), dyspnea (24-30%), myalgia, neuropathy, sleep disturbances, anxiety/depression, and post-exertional malaise (PEM, ME/CFS-like).
-Distinctions via clustering: Long COVID emphasizes respiratory (anosmia/dysgeusia, cough, sputum) and multi-system (psychiatric/sleep, e.g., insomnia, memory issues) symptoms; higher in earlier variants (e.g., Delta/Omicron).
researchgate.net/publication/39…
- PVS highlights neurological (burning paresthesia, numbness, visual disturbances, heat intolerance, tachycardia) and dermatological (herpes zoster) symptoms; less anosmia/dyspnea.
3.Unique Complications:
-Long COVID: Pulmonary fibrosis, new-onset diabetes, venous thromboembolism, dysautonomia (POTS), multi-organ impairment (e.g., post-ICU overlap); prevalence 30-50% post-infection.
-PVS: Vaccine-specific like myocarditis/pericarditis (young males, mRNA vaccines), VITT (adenoviral vaccines), autoimmune hepatitis, transverse myelitis; milder/self-limiting in most (0.2-1.4% chronic/PVS).
journals.viamedica.pl/medical_resear…
4.Demographics/Risk Factors:
-Long COVID: Females, older adults, severe initial infection, comorbidities (e.g., diabetes), regional variations (higher in South America).
-PVS: Young males (myocarditis), vaccine type-dependent (mRNA for cardiac, adenoviral for thrombotic).
news.yale.edu/2025/02/19/imm…
5.Evaluation Approach:
Detailed history (infection vs. vaccination confirmation via PCR/antibodies) with symptom scoring (e.g., PASC index ≥12) to rule out “mimics” (e.g., ME/CFS, fibromyalgia).
sciencedirect.com/science/articl…
2/N
1.Timing of Onset:
-Long COVID symptoms typically emerge or persist 4-12 weeks post-infection resolution, with gradual evolution and a duration ≥2-3 months-years.
-PVS often has acute onset within hours to days post-vaccination (e.g., 1-7 days for initial fatigue/brain fog), progressing to chronicity in <1% of cases, with shorter latency to severe manifestations.
sciencedirect.com/science/articl…
2.Symptom Profiles:
-Core overlaps include fatigue (58-70%), headache (44%), cognitive impairment/brain fog (27-40%), dyspnea (24-30%), myalgia, neuropathy, sleep disturbances, anxiety/depression, and post-exertional malaise (PEM, ME/CFS-like).
-Distinctions via clustering: Long COVID emphasizes respiratory (anosmia/dysgeusia, cough, sputum) and multi-system (psychiatric/sleep, e.g., insomnia, memory issues) symptoms; higher in earlier variants (e.g., Delta/Omicron).
researchgate.net/publication/39…
- PVS highlights neurological (burning paresthesia, numbness, visual disturbances, heat intolerance, tachycardia) and dermatological (herpes zoster) symptoms; less anosmia/dyspnea.
3.Unique Complications:
-Long COVID: Pulmonary fibrosis, new-onset diabetes, venous thromboembolism, dysautonomia (POTS), multi-organ impairment (e.g., post-ICU overlap); prevalence 30-50% post-infection.
-PVS: Vaccine-specific like myocarditis/pericarditis (young males, mRNA vaccines), VITT (adenoviral vaccines), autoimmune hepatitis, transverse myelitis; milder/self-limiting in most (0.2-1.4% chronic/PVS).
journals.viamedica.pl/medical_resear…
4.Demographics/Risk Factors:
-Long COVID: Females, older adults, severe initial infection, comorbidities (e.g., diabetes), regional variations (higher in South America).
-PVS: Young males (myocarditis), vaccine type-dependent (mRNA for cardiac, adenoviral for thrombotic).
news.yale.edu/2025/02/19/imm…
5.Evaluation Approach:
Detailed history (infection vs. vaccination confirmation via PCR/antibodies) with symptom scoring (e.g., PASC index ≥12) to rule out “mimics” (e.g., ME/CFS, fibromyalgia).
sciencedirect.com/science/articl…
2/N
Detailed Lab Breakdown
1.Routine labs (CBC, electrolytes, LFTs/RFTs, CRP/ESR) show no reliable differences and often fail to distinguish either from healthy states.
-Advanced biomarkers focus on viral persistence, immune profiling, and autoimmunity.
-Shared elevations: Pro-inflammatory cytokines (IL-1β/6, TNF-α), chemokines, D-dimers, oxidative stress markers.
mdpi.com/1422-0067/26/1…
-Some studies highlight proteomic/immune distinctions for better separation.
medrxiv.org/content/10.110…
2.Viral Detection:
-Long COVID: Persistent full-length SARS-CoV-2 RNA/nucleocapsid (N) protein in plasma/monocytes/tissues (digital PCR/IHC, up to 15-24 months).
sciencedirect.com/science/articl…
-PVS: Vaccine-modified spike (S1/S2) protein/mRNA in plasma/exosomes (up to 6-12 months), no N protein.
news.yale.edu/2025/02/19/imm…
3.Immune Markers:
-Long COVID: T-cell exhaustion (PD-1+ CD8+), higher CD14+CD16+ monocytes, EBV/herpes reactivation (PCR/IgG), antiplasmin in microclots.
mdpi.com/1422-0067/26/1…
-PVS: Lower effector CD4+ T cells, higher TNF-α+ CD8+ T cells, reduced spike antibodies (if no infection); blood markers like altered von Willebrand factor distinguish from normal vax response.
pmc.ncbi.nlm.nih.gov/articles/PMC10…
4.Autoantibodies:
- Shared: Anti-nuclear, anti-cardiolipin, anti-IFN, anti-ACE2/AT1R.
-Long COVID-specific: Broader post-infectious (e.g., functional autoantibodies predicting duration).
medrxiv.org/content/10.110…
- PVS-specific: Anti-PF4 (VITT, with thrombocytopenia/high D-dimers), anti-mitochondrial/GPIbα/ANCA, anti-PEG (from excipients).
journals.viamedica.pl/medical_resear…
5.Other Labs:
-Troponins/BNP elevated in cardiac involvement (more acute in PVS); proteomics (e.g., CXCL5/AP3S2 panels) for discrimination.
-Nucleocapsid IgG confirms prior infection (positive long COVID, negative pure PVS).
sciencedirect.com/science/articl…
6.Approach:
I would advise tiered testing: Start with nucleocapsid/spike assays, flow cytometry for T-cell subsets, then specialized panels, if your lab carries these(e.g., cytokine multiplex).
3/N
1.Routine labs (CBC, electrolytes, LFTs/RFTs, CRP/ESR) show no reliable differences and often fail to distinguish either from healthy states.
-Advanced biomarkers focus on viral persistence, immune profiling, and autoimmunity.
-Shared elevations: Pro-inflammatory cytokines (IL-1β/6, TNF-α), chemokines, D-dimers, oxidative stress markers.
mdpi.com/1422-0067/26/1…
-Some studies highlight proteomic/immune distinctions for better separation.
medrxiv.org/content/10.110…
2.Viral Detection:
-Long COVID: Persistent full-length SARS-CoV-2 RNA/nucleocapsid (N) protein in plasma/monocytes/tissues (digital PCR/IHC, up to 15-24 months).
sciencedirect.com/science/articl…
-PVS: Vaccine-modified spike (S1/S2) protein/mRNA in plasma/exosomes (up to 6-12 months), no N protein.
news.yale.edu/2025/02/19/imm…
3.Immune Markers:
-Long COVID: T-cell exhaustion (PD-1+ CD8+), higher CD14+CD16+ monocytes, EBV/herpes reactivation (PCR/IgG), antiplasmin in microclots.
mdpi.com/1422-0067/26/1…
-PVS: Lower effector CD4+ T cells, higher TNF-α+ CD8+ T cells, reduced spike antibodies (if no infection); blood markers like altered von Willebrand factor distinguish from normal vax response.
pmc.ncbi.nlm.nih.gov/articles/PMC10…
4.Autoantibodies:
- Shared: Anti-nuclear, anti-cardiolipin, anti-IFN, anti-ACE2/AT1R.
-Long COVID-specific: Broader post-infectious (e.g., functional autoantibodies predicting duration).
medrxiv.org/content/10.110…
- PVS-specific: Anti-PF4 (VITT, with thrombocytopenia/high D-dimers), anti-mitochondrial/GPIbα/ANCA, anti-PEG (from excipients).
journals.viamedica.pl/medical_resear…
5.Other Labs:
-Troponins/BNP elevated in cardiac involvement (more acute in PVS); proteomics (e.g., CXCL5/AP3S2 panels) for discrimination.
-Nucleocapsid IgG confirms prior infection (positive long COVID, negative pure PVS).
sciencedirect.com/science/articl…
6.Approach:
I would advise tiered testing: Start with nucleocapsid/spike assays, flow cytometry for T-cell subsets, then specialized panels, if your lab carries these(e.g., cytokine multiplex).
3/N
Detailed Radiology Breakdown:
Imaging aids in assessing organ-specific damage but shows overlaps (e.g., inflammation/fibrosis).
-Cardiac MRI is key for myocarditis,
-Brain imaging for neurological symptoms.
-Recent work suggests vaccine-type influences (e.g., mRNA-associated lymph node hypermetabolism).
ovid.com/journals/rimv/…
1.Cardiac Imaging:
-MRI with late gadolinium enhancement (LGE) shows subepicardial/mid-myocardial scarring in both; more common/persistent in PVS myocarditis (up to 60-70% abnormal).
thelancet.com/journals/eclin…
- Long COVID: Diffuse edema/T2 hyperintensity, reduced ejection fraction in severe cases. PVS: Focal LGE, quicker resolution; echocardiography for pericardial effusion.
pubs.rsna.org/doi/full/10.11…
2.Pulmonary Imaging:
- CT shows ground-glass opacities/fibrosis in long COVID (post-viral); rare in PVS unless overlapping.
mdpi.com/1422-0067/26/1…
3.Neurological Imaging:
Brain MRI: White matter hyperintensities, microbleeds in both; PVS more CNS-specific (e.g., demyelination in myelitis).
pmc.ncbi.nlm.nih.gov/articles/PMC10…
4. Others:
-Ultrasound for thrombosis (VITT in PVS).
pmc.ncbi.nlm.nih.gov/articles/PMC11…
I would advise: MRI first for suspected myocarditis with serial follow-up imaging to monitor resolution (faster in PVS).
thelancet.com/journals/eclin…
4/N
Imaging aids in assessing organ-specific damage but shows overlaps (e.g., inflammation/fibrosis).
-Cardiac MRI is key for myocarditis,
-Brain imaging for neurological symptoms.
-Recent work suggests vaccine-type influences (e.g., mRNA-associated lymph node hypermetabolism).
ovid.com/journals/rimv/…
1.Cardiac Imaging:
-MRI with late gadolinium enhancement (LGE) shows subepicardial/mid-myocardial scarring in both; more common/persistent in PVS myocarditis (up to 60-70% abnormal).
thelancet.com/journals/eclin…
- Long COVID: Diffuse edema/T2 hyperintensity, reduced ejection fraction in severe cases. PVS: Focal LGE, quicker resolution; echocardiography for pericardial effusion.
pubs.rsna.org/doi/full/10.11…
2.Pulmonary Imaging:
- CT shows ground-glass opacities/fibrosis in long COVID (post-viral); rare in PVS unless overlapping.
mdpi.com/1422-0067/26/1…
3.Neurological Imaging:
Brain MRI: White matter hyperintensities, microbleeds in both; PVS more CNS-specific (e.g., demyelination in myelitis).
pmc.ncbi.nlm.nih.gov/articles/PMC10…
4. Others:
-Ultrasound for thrombosis (VITT in PVS).
pmc.ncbi.nlm.nih.gov/articles/PMC11…
I would advise: MRI first for suspected myocarditis with serial follow-up imaging to monitor resolution (faster in PVS).
thelancet.com/journals/eclin…
4/N
Nuclear medicine breakdown:
FDG-PET/CT Scan
-One potential nuclear medicine test to help differentiate long COVID from long vax syndrome is an 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scan.
-This imaging modality uses a radioactive glucose analog (FDG) to detect areas of increased
metabolic activity, often in lymph nodes, brain, or other tissues affected by inflammation or immune responses.
How It Could Differentiate the Conditions:
1.Lymphadenopathy Patterns:
-In long vax syndrome, FDG-PET/CT commonly shows persistent unilateral (ipsilateral) axillary hypermetabolic lymphadenopathy on the side of vaccination, which can last months (e.g., median 230 days in some cases). This reflects a localized immune response to the vaccine's spike protein.
-In long COVID, lymphadenopathy is rarer and typically diffuse or systemic (e.g., involving cervical, thoracic, or abdominal nodes), if present at all, due to broader viral dissemination.
2.Brain Metabolism (Emerging Evidence):
-Long COVID often reveals focal hypometabolism in frontal/parietal lobes (linked to brain fog, fatigue) and transient hypermetabolism in limbic areas (e.g., amygdala, hippocampus) peaking 2–6 months post-infection, with sometimes a recovery by 12 months.
-Limited data exists for long vax, but neurological symptoms (e.g., neuropathy, burning sensations) may show different patterns, such as less pronounced limbic involvement or more peripheral nerve-related changes.
-No direct comparative studies confirm this yet, but it could be explored in research settings.
3.Other nuclear tests like SPECT brain perfusion imaging show promise for long COVID (e.g., detecting emotional center overactivity), but lack differentiation data for long vax
eurjmedres.biomedcentral.com/articles/10.11…
5/N
FDG-PET/CT Scan
-One potential nuclear medicine test to help differentiate long COVID from long vax syndrome is an 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scan.
-This imaging modality uses a radioactive glucose analog (FDG) to detect areas of increased
metabolic activity, often in lymph nodes, brain, or other tissues affected by inflammation or immune responses.
How It Could Differentiate the Conditions:
1.Lymphadenopathy Patterns:
-In long vax syndrome, FDG-PET/CT commonly shows persistent unilateral (ipsilateral) axillary hypermetabolic lymphadenopathy on the side of vaccination, which can last months (e.g., median 230 days in some cases). This reflects a localized immune response to the vaccine's spike protein.
-In long COVID, lymphadenopathy is rarer and typically diffuse or systemic (e.g., involving cervical, thoracic, or abdominal nodes), if present at all, due to broader viral dissemination.
2.Brain Metabolism (Emerging Evidence):
-Long COVID often reveals focal hypometabolism in frontal/parietal lobes (linked to brain fog, fatigue) and transient hypermetabolism in limbic areas (e.g., amygdala, hippocampus) peaking 2–6 months post-infection, with sometimes a recovery by 12 months.
-Limited data exists for long vax, but neurological symptoms (e.g., neuropathy, burning sensations) may show different patterns, such as less pronounced limbic involvement or more peripheral nerve-related changes.
-No direct comparative studies confirm this yet, but it could be explored in research settings.
3.Other nuclear tests like SPECT brain perfusion imaging show promise for long COVID (e.g., detecting emotional center overactivity), but lack differentiation data for long vax
eurjmedres.biomedcentral.com/articles/10.11…
5/N
Biopsy Breakdown (Heart and Other Organs)
Biopsies confirm tissue-level pathology but are invasive and we reserve this for special cases.
We prefer Endomyocardial biopsy (EMB) for heart, others if indicated and possible. Etherical concerns need attention.
pmc.ncbi.nlm.nih.gov/articles/PMC12…
1.Heart (EMB):
-Both: Lymphocytic myocarditis, microvascular thrombosis.
pmc.ncbi.nlm.nih.gov/articles/PMC95…
- Long COVID: Stronger CD8+ T-cell dominance, viral RNA/N protein.
pmc.ncbi.nlm.nih.gov/articles/PMC95…
-PVS: Milder CD4+ infiltrates, spike-only; rare giant cell myocarditis.
pmc.ncbi.nlm.nih.gov/articles/PMC12…
-snRNA-seq discriminates immune profiles.
sciencedirect.com/science/articl…
2.Other Organs:
Lungs (long COVID: Fibrosis, viral antigens; rare in PVS).
recovercovid.org/news/recovers-…
Brain (autopsy: Microglial activation in both; more neuroinflammation in long COVID).
mdpi.com/1422-0067/26/1…
Gut/skin: Viral persistence in long COVID.
recovercovid.org/news/recovers-…
Liver (autoimmune hepatitis in PVS).
journals.viamedica.pl/medical_resear…
Important bottom-line: Try less risky tests first; biopsy is a last resort for unclear situations!
Some other Tests you might need in determining between LongCovid and PVS
1.Functional Tests: Autonomic testing (tilt table for POTS, more in long COVID); neurocognitive batteries (distinguish severity).
pmc.ncbi.nlm.nih.gov/articles/PMC10…
2.Advanced Omics: Proteomics/genomics for biomarkers and machine learning symptom models.
researchgate.net/publication/39…
6/N
Biopsies confirm tissue-level pathology but are invasive and we reserve this for special cases.
We prefer Endomyocardial biopsy (EMB) for heart, others if indicated and possible. Etherical concerns need attention.
pmc.ncbi.nlm.nih.gov/articles/PMC12…
1.Heart (EMB):
-Both: Lymphocytic myocarditis, microvascular thrombosis.
pmc.ncbi.nlm.nih.gov/articles/PMC95…
- Long COVID: Stronger CD8+ T-cell dominance, viral RNA/N protein.
pmc.ncbi.nlm.nih.gov/articles/PMC95…
-PVS: Milder CD4+ infiltrates, spike-only; rare giant cell myocarditis.
pmc.ncbi.nlm.nih.gov/articles/PMC12…
-snRNA-seq discriminates immune profiles.
sciencedirect.com/science/articl…
2.Other Organs:
Lungs (long COVID: Fibrosis, viral antigens; rare in PVS).
recovercovid.org/news/recovers-…
Brain (autopsy: Microglial activation in both; more neuroinflammation in long COVID).
mdpi.com/1422-0067/26/1…
Gut/skin: Viral persistence in long COVID.
recovercovid.org/news/recovers-…
Liver (autoimmune hepatitis in PVS).
journals.viamedica.pl/medical_resear…
Important bottom-line: Try less risky tests first; biopsy is a last resort for unclear situations!
Some other Tests you might need in determining between LongCovid and PVS
1.Functional Tests: Autonomic testing (tilt table for POTS, more in long COVID); neurocognitive batteries (distinguish severity).
pmc.ncbi.nlm.nih.gov/articles/PMC10…
2.Advanced Omics: Proteomics/genomics for biomarkers and machine learning symptom models.
researchgate.net/publication/39…
6/N
I may have forgotten to mention some points, or references. Please feel free to comment and add!
Most important take-away:
THIS IS MULTIDISCIPLINARY WORK based on science facts, not here-say, anecdotes, or conspiratory stands! Patientcare is our ultimate goal!
End.
Most important take-away:
THIS IS MULTIDISCIPLINARY WORK based on science facts, not here-say, anecdotes, or conspiratory stands! Patientcare is our ultimate goal!
End.
Sorry, *ethical, not Etherical!!! 😂
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