Tag: post-vaccination syndrome

Vitamin D in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After COVID-19 or Vaccination: A Randomized Controlled Trial

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) can develop as post-vaccination syndrome (PVS) or Post-Acute Sequelae of SARS-CoV-2 infection (PASC). In our prior retrospective study, most patients with PVS who developed ME/CFS had vitamin D insufficiency or deficiency. We evaluated the efficacy of vitamin D replacement therapy guidance for ME/CFS symptom improvement in patients with vitamin D insufficiency or deficiency.

Methods: This open-label randomized controlled trial enrolled 91 participants with ME/CFS as PVS or PASC and serum 25(OH) vitamin D < 30 ng/mL across five clinical sites. Participants were randomized 1:1 to intervention (active vitamin D preparation plus vitamin D replacement therapy guidance: 25 μg daily supplementation, dietary counseling, sun exposure, and exercise) or control (active vitamin D preparation alone) for 12 weeks. The primary endpoint was the change in ME/CFS symptom count from screening to Week 12.

Results: Mean symptom change was -6.7 in the intervention group versus -1.2 in the control group (between-group difference -5.6; 95% CI: -7.2, -3.9; p < 0.001). Serum 25(OH) vitamin D improved from 18.6 to 27.1 ng/mL in the intervention group, while the control group showed a decreasing trend (between-group difference 10.2 ng/mL; 95% CI: 7.9, 12.5). Achievement of <8 symptoms (i.e., no longer meeting ME/CFS diagnostic criteria) was significantly higher in the intervention group, with 16 participants achieving this threshold compared to 1 in the control group (p < 0.001). Subgroup analyses showed consistent benefit in both PVS (n = 56) and PASC (n = 29) cohorts.

Conclusions: Vitamin D replacement therapy guidance significantly reduced ME/CFS symptoms along with improvement of serum 25(OH) vitamin D levels in patients with vitamin D insufficiency or deficiency who developed ME/CFS as PVS or PASC.

Source: Kodama S, Nakata M, Konishi N, Yoshino M, Fujisawa A, Naganuma M, Kobayashi Y, Hirai Y, Kitagawa A, Miyokawa M, Mishima R, Teramukai S, Fukushima M. Vitamin D in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After COVID-19 or Vaccination: A Randomized Controlled Trial. Nutrients. 2026 Feb 3;18(3):521. doi: 10.3390/nu18030521. PMID: 41683343. https://www.mdpi.com/2072-6643/18/3/521 (Full text)

Overlapping Clinical Presentation of Long COVID and Postacute COVID-19 Vaccination Syndrome: Phenotypes, Severity, and Biomarkers

Abstract:

Background: Postacute sequelae of COVID-19 (PASC), also known as long COVID, and postacute COVID-19 vaccination syndrome (PACVS) present overlapping but distinct clinical challenges. We hypothesize that PASC and PACVS share clinical features but differ in symptom patterns and biomarker profiles. This study aims to identify differences in presentation and distinguish immunologic biomarkers relevant to general clinical practice.

Methods: This cross-sectional study analyzed 181 patients from a PASC clinic at Columbia University Irving Medical Center. Patients were divided into PASC with myalgic encephalomyelitis/chronic fatigue syndrome (MECFS), PASC without MECFS (LC), and PACVS groups. Prevalence and severity of self-reported symptoms, as well as immunologic abnormalities, were compared across groups.

Results: Fatigue was the most common symptom (Total: 88.95%; MECFS: 100.00%; PACVS: 92.86%; LC: 78.05%). The MECFS group generally reported more symptoms across all organ systems. The PACVS group reported higher rates of atypical chief complaints such as peripheral neuropathy (17.9%), tinnitus (7.1%), and rash (10.7%) compared to the other groups (P = <.01). Functional impairment was comparable between the MECFS and PACVS groups and less severe in the LC group. All groups had high rates of autoantibody positivity and cytokine elevation. The PACVS group showed significantly higher rates of anticardiolipin IgM (PACVS 42.9%, LC 11.6%; P = .02) and anti-U1-RNP (PACVS 21.4%, LC 2.3%; P = .04) positivity compared to the LC group.

Conclusions: PASC and PACVS share symptom overlap but exhibit distinct biomarker patterns, particularly elevated autoantibody levels in PACVS. These findings suggest autoimmune involvement, warranting further investigation for targeted therapies.

Source: Purpura L, Heisler T, Palmer S, Shah J, Graham A, Seo GY, Sturiza A, Javier X, Pinto G, Rosa A, Bosco J, Reis K, Sobieszczyk ME, Yin MT. Overlapping Clinical Presentation of Long COVID and Postacute COVID-19 Vaccination Syndrome: Phenotypes, Severity, and Biomarkers. Clin Infect Dis. 2026 Jan 9:ciaf624. doi: 10.1093/cid/ciaf624. Epub ahead of print. PMID: 41510565. https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaf624/8417802 (Full text)

Complex chronic adverse events following immunization: a systemic critique and reform proposal for vaccine pharmacovigilance

Abstract:

The COVID-19 pandemic has renewed attention to complex chronic health conditions that challenge conventional biomedical paradigms. Syndromes such as postural orthostatic tachycardia syndrome and myalgic encephalomyelitis/chronic fatigue syndrome have gained broader visibility through the lens of Long COVID. As global vaccination campaigns expanded, a subset of individuals began reporting similarly persistent, multisystem symptoms following COVID-19 immunization-informally referred to as post-COVID-19 vaccination syndrome.

These presentations, which include dysautonomia, neuropathic pain, post-exertional malaise, and cognitive dysfunction, resemble post-infectious syndromes and may involve shared immune-related mechanisms. Although no causal relationship to vaccination has been established, these cases-together with comparable reports following other vaccines-highlight limitations in current vaccine safety systems for detecting and evaluating complex chronic outcomes.

This article introduces the concept of complex chronic adverse events following immunization (CC-AEFIs) as a pragmatic, surveillance-oriented framework to support the systematic identification and investigation of such cases. CC-AEFIs are not syndromic diagnoses but a higher-order category encompassing persistent, multifactorial conditions that may follow immunization yet challenge existing pharmacovigilance definitions and tools.

These conditions often involve multiple organ systems, delayed onset, fluctuating trajectories, diagnostic ambiguity, and symptom heterogeneity. Drawing on the author’s lived experience as an affected patient and integrating clinical, regulatory, and experiential evidence, the analysis examines structural and epistemic limitations across the pharmacovigilance continuum-from underrecognition in clinical settings to analytic exclusion and constrained governance.

It concludes by proposing reforms to strengthen safety-system responsiveness, including enhanced diagnostic training, longitudinal surveillance, patient-reported outcome integration, and analytic transparency. Addressing these limitations is essential to sustain public trust, ensure equitable care, and uphold the scientific integrity of immunization programs.

Source: Kenny TA. Complex chronic adverse events following immunization: a systemic critique and reform proposal for vaccine pharmacovigilance. Ther Adv Drug Saf. 2025 Dec 24;16:20420986251395925. doi: 10.1177/20420986251395925. PMID: 41466718; PMCID: PMC12743803. https://pmc.ncbi.nlm.nih.gov/articles/PMC12743803/ (Full text)

Post-COVID-19 Vaccination (or Long Vax) Syndrome: Putative Manifestation, Pathophysiology, and Therapeutic Options

Abstract:

With the global rollout of COVID-19 vaccines, vaccine safety remains a priority. Emerging concerns have raised the potential risk of a long COVID-like syndrome following vaccination, informally called long Vax and provisionally termed post-COVID-19 vaccination syndrome (PCVS). Our narrative review describes the putative manifestation, pathophysiology, and therapeutic approaches of PCVS based on the available evidence, mostly from case reports/series and observational studies.

Our review noted that PCVS typically manifests within days to weeks post-vaccination, with symptoms lasting months to years. PCVS may present as recognized diagnoses such as postural orthostatic tachycardia syndrome (POTS), small-fibre neuropathy (SFN), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), or as long-term sequelae of myocarditis, vaccine-induced thrombotic thrombocytopaenia (VITT), or immune thrombocytopaenia purpura (ITP). Symptomatically, PCVS overlaps with long COVID, such as fatigue and brain fog, but PCVS may involve more frequent paraesthesia and less dyspnoea.

We also review pathophysiological hypotheses of PCVS, focussing on the vaccine-derived spike protein and related immune responses. Finally, we discuss potential therapies used to treat patients with PCVS or related conditions, primarily documented in case reports/series, which could guide future clinical research. Overall, PCVS remains a poorly understood condition that requires more research to elucidate its prevalence, prognosis, risk factors, and treatments.

Source: Yong SJ, Kenny TA, Halim A, Munipalli B, Alhashem YN, AlSaihati H, Al-Subaie MF, Al Kaabi NA, Al Fares MA, Garout M, Sabour AA, Alshiekheid MA, Almansour ZH, Alotaibi J, Alrasheed HA, Alamri AA, Albayat H, Alamodi AS, Tombuloglu H, Mohapatra RK, Hazazi A, Rabaan AA. Post-COVID-19 Vaccination (or Long Vax) Syndrome: Putative Manifestation, Pathophysiology, and Therapeutic Options. Rev Med Virol. 2025 Sep;35(5):e70070. doi: 10.1002/rmv.70070. PMID: 40944962. https://pubmed.ncbi.nlm.nih.gov/40944962/

Efficacy of vitamin D replacement therapy on 28 cases of myalgic encephalomyelitis/chronic fatigue syndrome after COVID-19 vaccination

Abstract:

Background: Prolonged symptoms have been reported following both COVID-19 infection and vaccination, with some cases leading to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Of 80 patients presenting to our hospital with postvaccination syndrome, 28 met the diagnostic criteria for ME/CFS. We conducted a retrospective study on these 28 patients.

Methods: We measured serum 25-hydroxyvitamin D levels in 28 patients who developed ME/CFS after COVID-19 vaccination between August 2022 and February 2024. Vitamin D replacement therapy included dietary counseling, sun exposure recommendations, and oral vitamin D supplementation. We evaluated changes in blood vitamin D levels and symptom improvement.

Results: At initial visit, 27 of 28 patients diagnosed with ME/CFS had insufficient or deficient serum 25-hydroxyvitamin D levels (16 ± 4 ng/mL, mean ± SD). Following vitamin D replacement therapy, we observed an increase in blood vitamin D levels (28 ± 5 ng/mL) associated with a decrease in ME/CFS diagnostic symptoms (from 10.3 ± 2.1 to 3.3 ± 2.0). Notably, 23 of 28 patients (82%) no longer met ME/CFS diagnostic criteria after the therapy. Among the symptoms, sleep problems showed the most improvement (71%), followed by autonomic symptoms (68%).

Conclusions: For patients developing ME/CFS after COVID-19 vaccination with insufficient or deficient vitamin D levels, appropriate vitamin D replacement therapy under medical guidance may lead to symptomatic relief. We are preparing a randomized controlled trial to evaluate the efficacy of vitamin D replacement therapy in individuals with ME/CFS who have developed vitamin D deficiency following COVID-19 infection or vaccination.

Source: Kodama S, Konishi N, Hirai Y, Fujisawa A, Nakata M, Teramukai S, Fukushima M. Efficacy of vitamin D replacement therapy on 28 cases of myalgic encephalomyelitis/chronic fatigue syndrome after COVID-19 vaccination. Nutrition. 2025 Feb 18;134:112718. doi: 10.1016/j.nut.2025.112718. Epub ahead of print. PMID: 40090177. https://www.sciencedirect.com/science/article/pii/S089990072500036X (Full text)

Immunological and Antigenic Signatures Associated with Chronic Illnesses after COVID-19 Vaccination

Summary:

COVID-19 vaccines have prevented millions of COVID-19 deaths. Yet, a small fraction of the population reports a chronic debilitating condition after COVID-19 vaccination, often referred to as post-vaccination syndrome (PVS). To explore potential pathobiological features associated with PVS, we conducted a decentralized, cross-sectional study involving 42 PVS participants and 22 healthy controls enrolled in the Yale LISTEN study.

Compared with controls, PVS participants exhibited differences in immune profiles, including reduced circulating memory and effector CD4 T cells (type 1 and type 2) and an increase in TNFα+ CD8 T cells. PVS participants also had lower anti-spike antibody titers, primarily due to fewer vaccine doses. Serological evidence of recent Epstein-Barr virus (EBV) reactivation was observed more frequently in PVS participants. Further, individuals with PVS exhibited elevated levels of circulating spike protein compared to healthy controls.

These findings reveal potential immune differences in individuals with PVS that merit further investigation to better understand this condition and inform future research into diagnostic and therapeutic approaches.

Source: Bornali Bhattacharjee, Peiwen Lu, Valter Silva Monteiro, Alexandra Tabachnikova, Kexin Wang, William B. Hooper, Victoria Bastos, Kerrie Greene, Mitsuaki Sawano, Christian Guirgis, Tiffany J. Tzeng, Frederick Warner, Pavlina Baevova, Kathy Kamath, Jack Reifert, Danice Hertz, Brianne Dressen, Laura Tabacof, Jamie Wood, Lily Cooke, Mackenzie Doerstling, Shadan Nolasco, Amer Ahmed, Amy Proal, David Putrino, Leying Guan, Harlan M. Krumholz, Akiko Iwasaki. Immunological and Antigenic Signatures Associated with Chronic Illnesses after COVID-19 Vaccination medRxiv 2025.02.18.25322379; doi: https://doi.org/10.1101/2025.02.18.25322379 https://www.medrxiv.org/content/10.1101/2025.02.18.25322379v1.full-text (Full text)

Clinical and Diagnostic Features of Post-Acute COVID-19 Vaccination Syndrome (PACVS)

Abstract:

Post-acute COVID-19 vaccination syndrome (PACVS) is a chronic disease triggered by SARS-CoV-2 vaccination (estimated prevalence 0.02%). PACVS is discriminated from the normal post-vaccination state by altered receptor antibodies, most notably angiotensin II type 1 and alpha-2B adrenergic receptor antibodies. Here, we investigate the clinical phenotype using a study registry encompassing 191 PACVS-affected persons (159 females/32 males; median ages: 39/42 years).

Unbiased clustering (modified Jaccard index) of reported symptoms revealed a prevalent cross-cohort symptomatology of malaise and chronic fatigue (>80% of cases). Overlapping clusters of (i) peripheral nerve dysfunction, dysesthesia, motor weakness, pain, and vasomotor dysfunction; (ii) cardiovascular impairment; and (iii) cognitive impairment, headache, and visual and acoustic dysfunctions were also frequently represented.

Notable abnormalities of standard serum markers encompassing increased interleukins 6 and 8 (>80%), low free tri-iodine thyroxine (>80%), IgG subclass imbalances (>50%), impaired iron storage (>50%), and increased soluble neurofilament light chains (>30%) were not associated with specific symptoms.

Based on these data, 131/191 participants fit myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and simultaneously also several other established dysautonomia syndromes. Furthermore, 31/191 participants fit none of these syndromes. In conclusion, PACVS could either be an outlier of ME/CFS or a dysautonomia syndrome sui generis.

Source: Mundorf AK, Semmler A, Heidecke H, Schott M, Steffen F, Bittner S, Lackner KJ, Schulze-Bosse K, Pawlitzki M, Meuth SG, Klawonn F, Ruhrländer J, Boege F. Clinical and Diagnostic Features of Post-Acute COVID-19 Vaccination Syndrome (PACVS). Vaccines (Basel). 2024 Jul 18;12(7):790. doi: 10.3390/vaccines12070790. PMID: 39066428; PMCID: PMC11281408. Mundorf AK, Semmler A, Heidecke H, Schott M, Steffen F, Bittner S, Lackner KJ, Schulze-Bosse K, Pawlitzki M, Meuth SG, Klawonn F, Ruhrländer J, Boege F. Clinical and Diagnostic Features of Post-Acute COVID-19 Vaccination Syndrome (PACVS). Vaccines (Basel). 2024 Jul 18;12(7):790. doi: 10.3390/vaccines12070790. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11281408/ (Full text)

Chronic Fatigue and Dysautonomia following COVID-19 Vaccination Is Distinguished from Normal Vaccination Response by Altered Blood Markers

Abstract:

SARS-CoV-2 mRNA vaccination can entail chronic fatigue/dysautonomia tentatively termed post-acute COVID-19 vaccination syndrome (PACVS). We explored receptor autoantibodies and interleukin-6 (IL-6) as somatic correlates of PACVS. Blood markers determined before and six months after first-time SARS-CoV-2 vaccination of healthy controls (N = 89; 71 females; mean/median age: 39/49 years) were compared with corresponding values of PACVS-affected persons (N = 191; 159 females; mean/median age: 40/39 years) exhibiting chronic fatigue/dysautonomia (≥three symptoms for ≥five months after the last SARS-CoV-2 mRNA vaccination) not due to SARS-CoV-2 infection and/or confounding diseases/medications.

Normal vaccination response encompassed decreases in 11 receptor antibodies (by 25-50%, p < 0.0001), increases in two receptor antibodies (by 15-25%, p < 0.0001) and normal IL-6. In PACVS, serological vaccination-response appeared significantly (p < 0.0001) altered, allowing discrimination from normal post-vaccination state (sensitivity = 90%, p < 0.0001) by increased Angiotensin II type 1 receptor antibodies (cut-off ≤ 10.7 U/mL, ROC-AUC = 0.824 ± 0.027), decreased alpha-2B adrenergic receptor antibodies (cut-off ≥ 25.2 U/mL, ROC-AUC = 0.828 ± 0.025) and increased IL-6 (cut-off ≤ 2.3 pg/mL, ROC-AUC = 0.850 ± 0.022). PACVS is thus indicated as a somatic syndrome delineated/detectable by diagnostic blood markers.

Source: Semmler A, Mundorf AK, Kuechler AS, Schulze-Bosse K, Heidecke H, Schulze-Forster K, Schott M, Uhrberg M, Weinhold S, Lackner KJ, Pawlitzki M, Meuth SG, Boege F, Ruhrländer J. Chronic Fatigue and Dysautonomia following COVID-19 Vaccination Is Distinguished from Normal Vaccination Response by Altered Blood Markers. Vaccines (Basel). 2023 Oct 26;11(11):1642. doi: 10.3390/vaccines11111642. PMID: 38005974. https://www.mdpi.com/2076-393X/11/11/1642 (Full text)

Post-Vaccination Syndrome: A Descriptive Analysis of Reported Symptoms and Patient Experiences After Covid-19 Immunization

Abstract:

Introduction: A chronic post-vaccination syndrome (PVS) after covid-19 vaccination has been reported but has yet to be well characterized.

Methods: We included 241 individuals aged 18 and older who self-reported PVS after covid-19 vaccination and who joined the online Yale Listen to Immune, Symptom and Treatment Experiences Now (LISTEN) Study from May 2022 to July 2023. We summarized their demographics, health status, symptoms, treatments tried, and overall experience.

Results: The median age of participants was 46 years (interquartile range [IQR]: 38 to 56), with 192 (80%) identifying as female, 209 (87%) as non-Hispanic White, and 211 (88%) from the United States. Among these participants with PVS, 127 (55%) had received the BNT162b2 [Pfizer-BioNTech] vaccine, and 86 (37%) received the mRNA-1273 [Moderna] vaccine. The median time from the day of index vaccination to symptom onset was three days (IQR: 1 day to 8 days). The time from vaccination to symptom survey completion was 595 days (IQR: 417 to 661 days). The median Euro-QoL visual analogue scale score was 50 (IQR: 39 to 70). The five most common symptoms were exercise intolerance (71%), excessive fatigue (69%), numbness (63%), brain fog (63%), and neuropathy (63%). In the week before survey completion, participants reported feeling unease (93%), fearfulness (82%), and overwhelmed by worries (81%), as well as feelings of helplessness (80%), anxiety (76%), depression (76%), hopelessness (72%), and worthlessness (49%) at least once. Participants reported a median of 20 (IQR: 13 to 30) interventions to treat their condition.

Conclusions: In this study, individuals who reported PVS after covid-19 vaccination had low health status, high symptom burden, and high psychosocial stress despite trying many treatments. There is a need for continued investigation to understand and treat this condition.

Source: Harlan M Krumholz, Yilun Wu, Mitsuaki Sawano, Rishi Shah, Tianna Zhou, Adith S Arun, Pavan Khosla, Shayaan Kaleem, Anushree Vashist, Bornali Bhattacharjee, Qinglan Ding, Yuan Lu, Cesar Caraballo, Frederick Warner, Chenxi Huang, Jeph Herrin, David Putrino, Danice Hertz, Brianne Dressen, Akiko Iwasaki. Post-Vaccination Syndrome: A Descriptive Analysis of Reported Symptoms and Patient Experiences After Covid-19 Immunization. medRxiv 2023.11.09.23298266; doi: https://doi.org/10.1101/2023.11.09.23298266 https://www.medrxiv.org/content/10.1101/2023.11.09.23298266v1 (Full text available as PDF file)