{ "condition": "PACVS – Post-Acute COVID-19 Vaccination Syndrome", "key": "pacvs", "last_updated": "2026-10-07T23:42:47.540056Z", "count": 15, "source": "PubMed (NCBI)", "studies": [ { "pmid": "42783201", "title": "Hospital Readmissions in Patients with Severe Acute Respiratory Syndrome: A Retrospective Study in Northeastern Brazil.", "pub_date": "2026-09-24", "journal": "Diseases (Basel, Switzerland)", "authors": "Wanderley, Raphael Omena, Dos Santos, Carmina Silva, Agra, Karine Ferreira, Gonçalves, Francisco Pirauá Alves et al.", "abstract": "Severe acute respiratory syndrome (SARS) remains an important cause of hospitalization and mortality, particularly among vulnerable populations. Understanding the factors associated with previous hospitalization may support more effective prevention and vaccination strategies. This study aimed to analyze the epidemiological profile of previous hospitalization among patients with SARS in the state of Pernambuco, Brazil. A quantitative, retrospective, cross-sectional study was conducted using data from the Influenza Epidemiological Surveillance System (SIVEP-Gripe), including 79,852 adult patients (≥18 years) notified with SARS in Pernambuco between 2021 and 2024. Sociodemographic, clinical, and vaccination-related variables were analyzed to identify factors associated with previous hospitalization. The prevalence of previous hospital admission (readmission history) was 6.6%. Patients with previous hospitalization had a significantly higher median age compared to those without previous hospitalization (66 vs. 63 years; Older adults and individuals with chronic comorbidities showed a higher prevalence of previous SARS hospitalization in Pernambuco. The findings show an association between influenza vaccination and a lower prevalence of previous SARS hospitalization and highlight the importance of post-discharge follow-up and epidemiological surveillance.", "url": "https://pubmed.ncbi.nlm.nih.gov/42783201/" }, { "pmid": "42774463", "title": "COVID-19 vaccination in relation to immune response and physical activity levels.", "pub_date": "2026-09-23", "journal": "Frontiers in public health", "authors": "Voulgaridi, Ioanna, Dinas, Petros C, Bogogiannidou, Zacharoula, Dadouli, Katerina et al.", "abstract": "The study aimed to determine the antibody response associated with physical activity (PA) levels and participants' individual characteristics following coronavirus disease 2019 (COVID-19) vaccination. The study population included adults vaccinated with either mRNA, adenovirus vector-based, or protein-based adjuvanted vaccines. The sample was derived from participants in a larger cohort study, whose blood samples were collected on days 21, 42, 90, and 180 following COVID-19 vaccination. We tested for immunoglobulin G (IgG) and immunoglobulin A (IgA) anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody responses, excluding samples collected on day 180, which were analyzed only for IgG antibody titers. Physical Activity (PA) levels were estimated using the short-form International PA Questionnaire (IPAQ), which measures usual weekly physical activity. Overall, 641 individuals participated in the study. Seropositivity for IgG antibodies was significantly higher among participants with moderate or high PA levels at 21 days (92.6 and 97.0%, respectively) than among those in the low exercise intensity group (70.4%) ( Encouraging moderate-to-high levels of exercise regimens before immunization could enhance vaccine efficacy, particularly among groups at risk of poor immune responses, such as older adults and those with chronic diseases.", "url": "https://pubmed.ncbi.nlm.nih.gov/42774463/" }, { "pmid": "42707810", "title": "Rare Complete Restoration of Intraepidermal Nerve Fibre Density by Immunoglobulins in Post-COVID Vaccination Syndrome-Associated Small Fibre Neuropathy: A Case Report and Literature Review.", "pub_date": "2026-09-08", "journal": "Cureus", "authors": "Schmidt-Krüger, Vanessa, Finsterer, Josef", "abstract": "This report describes the rare complete restoration of reduced intraepidermal nerve fibre density (IENFD) following the administration of intravenous immunoglobulins (IVIG) in a patient with post-acute COVID-19 vaccination syndrome (PACVS) that manifested, among other symptoms, as small-fibre neuropathy (SFN). The patient was a 53-year-old woman who developed SFN in June 2021 following her second BNT162b2 vaccination. Clinically, the SFN presented with symptoms including sensory disturbances, arterial hypotension, and orthostatic tachycardia. After eight cycles of IVIG therapy from June 2024 to February 2025, three years after the onset of PACVS, a significant improvement in the clinical SFN symptoms was observed. Additionally, the IENFD improved from 6 at the ankle and thigh before IVIG therapy to 9 at the ankle and 8 at the thigh after therapy. The skin biopsy in 2026 was unremarkable. The spike protein was detectable in peripheral blood mononuclear cells, as were vaccine plasmid DNA remnants in the skin biopsies before and after IVIG therapy. S100 protein staining was weakly positive before and after IVIG administration. We report the case of a 53-year-old female patient who presented with sensory and autonomic disturbances; following a skin biopsy, she was diagnosed with PACVS-associated SFN. Treatment with IVIG over several months led to an improvement in symptoms and a complete restoration of IENFD. This case highlights the importance of diagnosing PACVS-associated SFN and the beneficial effect of IVIG, which not only improves the clinical manifestations of SFN but also normalises IENFD.", "url": "https://pubmed.ncbi.nlm.nih.gov/42707810/" }, { "pmid": "42642464", "title": "Medical invalidation is associated with structural barriers in postacute immune mediated syndromes based on patient perspectives in Germany.", "pub_date": "2026-08-26", "journal": "Scientific reports", "authors": "Saad, Jad, Hensen, Jens, Bergelt, Corinna, Lerch, Seraina Petra", "abstract": "Post-acute immune-mediated syndromes (PAIMS), including Long COVID/Post-COVID (LC/PC), Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), and post-acute COVID-19 vaccination syndrome (PACVS), are characterized by persistent, multisystemic symptoms and significant healthcare challenges. A key issue is medical invalidation, defined as the dismissal or delegitimization of patients' reports of symptoms. This cross-sectional online study, conducted in Germany between October and December 2025 (N = 577), examined healthcare experiences, access barriers, and perceived invalidation. Although healthcare utilization was high, 87% of participants reported difficulties accessing appropriate treatment. Major barriers included lack of available therapies (60%) or not being taken seriously (26%). Perceived invalidation by medical personnel was moderate across all groups (LC: M = 2.80; ME/CFS: M = 2.99; PACVS: M = 3.03) and did not differ significantly (Welch-F(2, 190.50) = 2.87, p = 0.059) between groups. Invalidation occurred not only within healthcare settings but was particularly pronounced in interactions with authorities and workplaces. Social media and online communities served as important sources of information and support, especially among individuals with ME/CFS. Overall, the findings reveal substantial structural barriers in the care of PAIMS and highlight the need for improved clinical education, better care coordination, and stronger institutional recognition of these conditions.", "url": "https://pubmed.ncbi.nlm.nih.gov/42642464/" }, { "pmid": "42629447", "title": "Association between helminth infection and impaired SARS-CoV-2 antibody responses following COVID-19 vaccination: a cross-sectional study in Malawi.", "pub_date": "2026-08-22", "journal": "Scientific reports", "authors": "McCormack, Mhairi J, Banda, Louis, Kasenda, Stephen, Samikwa, Lyson et al.", "abstract": "Chronic helminth infections can modulate immune responses to infection and vaccination. This study explored the association between current helminth infection, including waterborne and soil-transmitted helminths (STHs), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralising and IgG antibody responses. Samples were collected cross-sectionally from participants across rural (Karonga) and urban (Lilongwe) regions in Malawi. Helminth infections were detected via real-time PCR in stool and urine samples, targeting Schistosoma spp., Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, and Trichuris trichiura. SARS-CoV-2 nAbs were measured using a human immunodeficiency virus (HIV)-based pseudotyped virus neutralisation assay. A nucleocapsid (N) protein enzyme-linked immunosorbent assay (ELISA) identified prior natural SARS-CoV-2 infection in vaccinated participants. IgG targeting the spike (S) protein was measured using an ELISA. Helminth infection was found to be associated with reduced nAb responses post coronavirus disease 2019 (COVID-19) vaccination, but not after natural SARS-CoV-2 infection. Generalised additive model analysis confirmed this interaction while considering covariates. IgG responses were also impaired among those helminth-infected. It should be investigated whether integrating pre-vaccination deworming improves vaccine responses in helminth-endemic regions.", "url": "https://pubmed.ncbi.nlm.nih.gov/42629447/" }, { "pmid": "42520426", "title": "Acute symptoms and subsequent post-acute symptoms following COVID-19 vaccination: A Danish population-based study.", "pub_date": "2026-07-29", "journal": "Public health", "authors": "Jensen, Christina Bisgaard, Sørensen, Andrea Skovgaard, Hansen, Kristoffer Torp, Hansen, Stefan Nygaard et al.", "abstract": "Acute symptoms are common following COVID-19 vaccination, yet it remains unclear if these reactions can manifest or progress into non-specific symptoms (e.g., headache, fatigue, muscle pain) beyond the acute phase. This study examines whether acute symptoms after COVID-19 vaccination increases the odds of subsequent post-acute symptoms, and whether this varies by vaccine hesitancy. Longitudinal cohort study. Using repeated measurements from the BiCoVac cohort of 911,613 Danes aged 16-65, acute symptoms were defined as the number of systemic symptoms within seven days following COVID-19 vaccination, while post-acute symptoms were assessed ≥ five weeks later using the 25-item Bodily Distress Syndrome checklist. Multiple logistic regressions with inverse probability weighting and robust standard errors were used. We included 93,268 observations representing 61,023 individuals. Compared to participants without acute symptoms, odds of high post-acute symptom burden were higher for individuals with one-four acute symptoms (OR = 2.13 (95% CI: 1.77-2.56)) and five + acute symptoms (OR = 6.37 (95% CI: 5.07-8.01)), particularly among vaccine-concerned individuals reporting five + acute symptoms (OR = 21.40 (95% CI: 9.98-45.89)). Findings highlight an association between acute and post-acute symptoms and further emphasize the impact of vaccine hesitancy.", "url": "https://pubmed.ncbi.nlm.nih.gov/42520426/" }, { "pmid": "42409655", "title": "Post-acute sequelae of COVID in children: Pulmonary assessment using impulse oscillometry and the effect of vaccination.", "pub_date": "2026-07-07", "journal": "Pediatrics and neonatology", "authors": "Chen, Chieh-Ho, Chen, Pei-Chi, Liu, Xiao-Ling, Wei, Chi-Hung et al.", "abstract": "Post-acute sequelae of SARS-CoV-2 infection (PASC), also known as long COVID syndrome (LCS), is characterized by persistent symptoms following SARS-CoV-2 infection and poses significant health challenges, particularly impacting pulmonary function in children. This study aims to evaluate the effect of COVID-19 vaccination on pulmonary function in children with PASC using standardized spirometry and impulse oscillometry (IOS). This prospective, observational study was conducted from July to September 2022, at the tertiary medical center of a children's hospital in Taiwan. Pediatric patients aged 6 to 18 years diagnosed with PASC were enrolled. Demographic data, vaccination status, and blood test results were collected. Pulmonary function was assessed using spirometry and IOS, measuring parameters such as respiratory resistance (R5, R20) and reactance (X5). Statistical analyses explored the association between IOS results and clinical symptoms, as well as vaccination status. Among 209 children, 78.7% were vaccinated. IOS detected abnormalities in 74.6%, with 12.0% diagnosed with obstructive lung disease (OLD) and 62.9% with small airway disease (SAD). Fatigue (56.0%) and dyspnea (52.0%) were most common in OLD, while chest pain (45.0%) and cough (41.7%) prevailed in SAD. Vaccinated children showed significantly lower respiratory resistance (R5, R20, p < 0.01) and improved reactance (X5, p < 0.001). Vaccination did not significantly reduce respiratory-related symptoms but it was associated with lower risks of decreased appetite (OR = 0.399) and sleep disturbance (OR = 0.345). COVID-19 vaccination may have a protective effect on pulmonary function in children with PASC, highlighting its mitigation of long-term respiratory complications. Further studies are needed to explore underlying mechanisms.", "url": "https://pubmed.ncbi.nlm.nih.gov/42409655/" }, { "pmid": "42395659", "title": "Post vaccination acute kidney injury and other renal complications after COVID-19 and influenza vaccination.", "pub_date": "2026-07-03", "journal": "World journal of nephrology", "authors": "Aye Kyaw, Yunn Honey, Yip, Pierre, See, Kay Choong", "abstract": "Vaccination remains a cornerstone of public health, yet concerns regarding serious adverse events continue to contribute to vaccine hesitancy. While systemic and local vaccine reactions are well described, renal complications such as acute kidney injury (AKI) and immune-mediated glomerular disease are less well characterised. With widespread and sustained use of coronavirus disease 2019 (COVID-19) and influenza vaccines, a comprehensive synthesis of reported renal adverse outcomes is needed. To synthesise and critically evaluate the existing evidence on AKI and other renal manifestations reported following influenza and COVID-19 vaccination. Specifically, it aims to characterise the spectrum of reported renal presentations, summarise clinical features and timelines described in case reports and case series, and contextualise these findings using population-level observational and pharmacovigilance data to assess the overall renal safety profile of these vaccines. We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. PubMed and EMBASE were searched from inception to 6 December 2025 for studies reporting renal outcomes following COVID-19 or influenza vaccination. Eligible studies included observational studies, pharmacovigilance analyses, case reports, and case series. Data on incidence, clinical presentation, timing of onset, management, and outcomes were extracted and synthesised narratively due to heterogeneity. Risk of bias in observational studies was assessed using the Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) tool. A total of 255 COVID-19 vaccine-related studies and 73 influenza vaccine-related studies met the inclusion criteria, supplemented by additional studies identified through reference screening. Population-level observational studies consistently demonstrated a low absolute risk of renal adverse outcomes following vaccination, with several studies reporting reduced AKI-related risk among vaccinated individuals. In contrast, pharmacovigilance analyses and case reports described serious instances of de novo or relapsing renal disease, including minimal change disease, immunoglobulin A nephropathy, membranous nephropathy, pauci-immune glomerulonephritis, and systemic inflammatory syndromes with secondary renal involvement. Symptom onset typically occurred within days to weeks of vaccination. Most cases responded favourably to supportive or disease-specific therapy, with recovery observed over weeks to months; irreversible renal outcomes were uncommon. Current evidence indicates that both COVID-19 and influenza vaccines are associated with a low population-level risk of adverse renal outcomes. Serious immune-mediated renal events have been reported in temporal association with vaccination, likely reflecting idiosyncratic immune responses or unmasking of pre-existing disease rather than a widespread nephrotoxic effect. The overall benefits of vaccination substantially outweigh potential renal risks. Ongoing surveillance and well-designed population-based studies remain essential to refine risk estimates and identify susceptible subgroups.", "url": "https://pubmed.ncbi.nlm.nih.gov/42395659/" }, { "pmid": "42357623", "title": "SARS-CoV-2 Infection and COVID-19 Vaccination Associated with Post-Acute Alopecia: Prevalence, Clinical Patterns, and Determinants Among Saudi Adults.", "pub_date": "2026-06-26", "journal": "Viruses", "authors": "Jareebi, Mohammad A, Abutaleb, Radwan A, Qassadi, Norah M, Akoor, Atheer A et al.", "abstract": "No abstract available.", "url": "https://pubmed.ncbi.nlm.nih.gov/42357623/" }, { "pmid": "42283396", "title": "Acute and chronic kidney injury following COVID-19 infection and vaccination: a narrative review.", "pub_date": "2026-06-12", "journal": "European journal of translational myology", "authors": "Saadat, Seyed Hassan, Javanbakht, Mohammad, Amini, Hossein, Rouhollahei, Mahboubeh et al.", "abstract": "This narrative review examines acute and chronic kidney injury following COVID-19 infection and vaccination, discussing the mechanism of SARS-CoV-2 entry into host cells through the ACE2 receptor - highly expressed in renal tissues - facilitating the viral invasion. Viral RNA has been detected in the urine of patients infected with SARS-CoV-2, suggesting direct renal involvement. The incidence of Acute Kidney Injuriy (AKI) among hospitalized COVID-19 patients was particularly higher in the early stages of the pandemic and largely varied by 29%-46%, depending on population studied and COVID-19 wave. Pathological findings include Acute Tubular Injury (ATI), collapsing glomerulopathy, and focal segmental glomerulosclerosis. Major risk factors for AKI comprise older age, male sex, diabetes, hypertension, cardiovascular disease, and preexisting Chronic Kidney Disease (CKD). AKI significantly increases mortality of COVID-19 patients, particularly in advanced stages of renal failure. CKD is also associated with severe COVID-19 outcomes, including increased hospitalization, intensive care admission, and mortality. Patients with CKD show a dose-dependent relationship between disease stage and adverse patient outcomes. This review further addresses renal complications following COVID-19 vaccination, which, although rare, encompass various immune-mediated glomerular diseases. Minimal Change Disease (MCD) is most frequently reported after COVID-19 vaccination, followed by IgA nephropathy, membranous nephropathy, anti-glomerular basement membrane (anti-GBM) nephritis, and ANCA-associated vasculitis. These conditions commonly present with hematuria, proteinuria, or nephrotic syndrome, and many respond to corticosteroid or immunosuppressive therapy. Other less frequent renal complications include thrombotic microangiopathy, acute tubulointerstitial nephritis, and IgG4-related nephritis. In conclusion, both COVID-19 infection and vaccination can be associated with a spectrum of renal manifestations ranging from AKI to CKD and immune-mediated glomerulopathies. Awareness, early detection, and multidisciplinary management are essential to reduce renal morbidity and improve patient outcomes.", "url": "https://pubmed.ncbi.nlm.nih.gov/42283396/" }, { "pmid": "42281871", "title": "Clinical predictors of SARS-CoV-2 vaccine immunogenicity in kidney transplant recipients at a rural center.", "pub_date": "2026-06-12", "journal": "World journal of transplantation", "authors": "Basuli, Debargha, Ross, Bonnie, Rebellato, Lorita M", "abstract": "Kidney transplant recipients (KTR) have impaired immune responses to vaccination and remain at increased risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection despite mRNA coronavirus disease 2019 (COVID-19) vaccination. Data from rural and medically underserved transplant populations remain limited. To evaluate serologic response to a two dose mRNA SARS-CoV-2 vaccination series and identify clinical factors associated with antibody response in KTR. This single center retrospective observational study included adult KTR who completed a two dose mRNA COVID-19 vaccination series and had post vaccination anti spike IgG testing performed using stored serum samples. Multivariable logistic regression was used to identify predictors of seroconversion. Among responders, linear regression was used to evaluate factors associated with quantitative antibody titers. A total of 108 KTR were included, of whom 63 (58.3%) achieved seroconversion. Higher estimated glomerular filtration rate showed independent association with seroconversion, while higher mycophenolic acid dose showed inverse association with response. Black race and basiliximab induction demonstrated association with seroconversion, though estimates were imprecise. Age, sex, body mass index, vaccine type, tacrolimus levels, and comorbidities were not independently associated with response. Among responders, no clinical or demographic variables were significantly associated with antibody titers. After two dose mRNA vaccination, fewer than two thirds of KTR developed detectable anti spike antibodies. Serologic response was associated with allograft function and antimetabolite exposure, while antibody magnitude was not explained by routine clinical factors in this cohort. These findings provide real world data from a rural transplant population and support consideration of augmented vaccination strategies in KTR.", "url": "https://pubmed.ncbi.nlm.nih.gov/42281871/" }, { "pmid": "42246405", "title": "A narrative review of COVID-19 epidemiology and mRNA vaccine impact in children <12 years during the omicron era (November 2021 - December 2025).", "pub_date": "2026-06-05", "journal": "Expert review of vaccines", "authors": "Zheng, Zhe, Yousefi, Mitra, Marks, Morgan, Dixit, Avika et al.", "abstract": "COVID-19 continues to pose a burden in children under 12 years of age during the Omicron era (November 2021 - December 2025). Following Omicron's emergence, SARS-CoV-2 seroprevalence increased rapidly, with most children infected by ages 2-4 years. Pediatric hospitalization rates declined after the initial Omicron wave but remained elevated in children under 2 years and in those with underlying conditions. While healthy children typically experience mild illnesses, severe outcomes-including hospitalization, admission to an intensive care unit, death, and multisystem inflammatory syndrome-can occur, particularly in unvaccinated children. This narrative review summarizes current evidence on pediatric COVID-19 epidemiology and vaccine impact, including infection rates, severe outcomes, post-acute COVID-19 syndrome (Long COVID), and mRNA vaccine effectiveness and uptake in high-income regions. A literature search included peer-reviewed publications, surveillance data, and reports from health agencies during the Omicron era. mRNA vaccines are effective in reducing pediatric COVID-19-related morbidity, but uptake remains low globally. Addressing parental concerns, improving vaccine accessibility, and promoting evidence-based communication are critical to increasing uptake. Given the continued disease burden and the potential for severe outcomes, ensuring access to mRNA COVID-19 vaccines for children at higher risk and for families who wish to vaccinate their children is beneficial.", "url": "https://pubmed.ncbi.nlm.nih.gov/42246405/" }, { "pmid": "42121078", "title": "Relationship between acute coronary syndrome and coronavirus disease 2019 infection and vaccination type: a retrospective observational study.", "pub_date": "2026-05-13", "journal": "BMC infectious diseases", "authors": "Gokdemir, Mehmet Tahir, Gokdemir, Gul Sahika", "abstract": "Studies have reported that the Coronavirus Disease 2019 (COVID-19) vaccine causes other serious health problems, including myocarditis, pericarditis, neurological problems, and problems resulting from the reactivation of chronic infections. There are no satisfactory studies on the relationship between late-stage COVID-19 disease and cardiovascular diseases, or even Acute coronary syndrome (ACS). Our study primarily aimed to compare the frequency of emergency department (ED) visits and mortality rates of patients diagnosed with acute coronary syndrome (ACS) before and after the COVID-19 pandemic. Secondly, we aimed to evaluate differences in demographic and laboratory characteristics between pre-pandemic and post-pandemic ACS patients. Finally, we aimed to investigate the association between COVID-19 vaccination status (unvaccinated, inactivated vaccine, and mRNA vaccine) and mortality outcomes in post-pandemic ACS patients. Data from 1,856 patients over the age of 18 diagnosed with ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI), and unstable angina pectoris (USAP) in 2023, post-pandemic, and 1,450 patients diagnosed in 2018, pre-pandemic, were analyzed. The incidence of ACS before and after the pandemic, its relationship with the presence of viral vector-based vaccination and mRNA vaccination, and demographic and laboratory results were retrospectively examined. Although the number of emergency department visits nearly doubled after the pandemic, mortality rates were similar (P = 0.595). Troponin I (P < 0.001), creatine kinase-MB (CK-MB) (P < 0.001), and prothrombin time (PT) (P = 0.016) levels were significantly increased in post-pandemic patients. Univariable analysis showed that being unvaccinated was associated with 2.88-fold higher odds of mortality (95% CI: 1.23-6.70), while in the multivariable analysis this association remained significant with 3.77-fold higher odds (95% CI: 1.04-13.65) (p = 0.014 and p = 0.043). Inactivated vaccine [OR 0.60 (95% CI: 0.36-1.01) and p = 0.054] and mRNA vaccine [OR 1.42 (95% CI: 0.85-2.36) and p = 0.177] did not have a significant effect on mortality. Post-pandemic mortality rates were similar to those before the pandemic. Being unvaccinated was found to be a significant associated with higher mortality. Vaccination type did not affect mortality. Cardiac and inflammatory marker levels were increased in post-pandemic ACS patients compared to pre-pandemic ACS patients.", "url": "https://pubmed.ncbi.nlm.nih.gov/42121078/" }, { "pmid": "42042830", "title": "Autoimmune Features of Post-COVID-19 Vaccination Syndrome and Their Impacts on the Renin-Angiotensin System.", "pub_date": "2026-04-27", "journal": "Vaccines", "authors": "Bellavite, Paolo, Di Fede, Giuseppe, Mantovani, Mauro, Zanolin, Elisabetta", "abstract": "One of the most critical aspects of post-acute COVID-19 syndrome (PACS) and post-acute COVID-19 vaccination syndrome (PACVS) is the presence of autoantibodies. These autoantibodies are directed against various receptors in the autonomic and cardiovascular systems, including those targeting proteins of the renin-angiotensin system (RAS). The RAS plays a central role in regulating vascular homeostasis, inflammation, and endothelial function. During SARS-CoV-2 infection, the interaction of the spike (S) protein with angiotensin-converting enzyme 2 (ACE2) can alter the balance of the RAS, favoring an imbalance towards the ACE/Angiotensin II/AT1R axis, known for its pro-inflammatory, pro-thrombotic, and vasoconstrictive properties. Similar pathological mechanisms also come into play in response to vaccinations that use the S protein as an antigen. Studies conducted by other groups and us on patients with PACS and PACVS have revealed the presence of autoantibodies directed against these RAS components and the mechanisms by which these antibodies can worsen the clinical situation. In particular, anti-ACE2, presumably formed by the anti-idiotype network or molecular mimicry, is correlated with PACVS symptoms in many patients. Furthermore, the presence of anti-MAS1 antibodies can reduce the efficiency of the ACE2/Angiotensin-(1-7)/MAS1 axis, which normally acts as a counter-regulator. Considering this evidence, an analysis of RAS molecules and the autoantibodies implicated in reactions to them may be useful for evaluating a state of persistent dysregulation associated with post-vaccination symptoms such as asthenia, headache, skin edema and bruising, cardiovascular alterations, and neurovegetative manifestations. Finally, we offer insights into diagnosing these multifaceted syndromes and working hypotheses to guide research into possible therapeutic approaches.", "url": "https://pubmed.ncbi.nlm.nih.gov/42042830/" }, { "pmid": "41990050", "title": "Comparison of lymphocyte populations, cytokine, and autoantibody profile in patients with rheumatoid arthritis: a study of cases with COVID-19 and controls without COVID-19.", "pub_date": "2026-04-17", "journal": "Journal of infection in developing countries", "authors": "Arias-Aponte, Julián, Acelas-Gonzalez, Gabriel E, Parra-Medina, Rafael, Monsalve-Córdoba, María L et al.", "abstract": "The SARS-CoV-2 pandemic is associated with the development of acute respiratory distress syndrome (ARDS) and post-COVID syndrome (PCS). PSC has been linked to autoimmune diseases, including rheumatoid arthritis (RA), a condition characterized by chronic joint pain driven by dysregulated immune response. This study aims to evaluate the impact of SARS-CoV-2 infection on patients with RA. A total of 300 RA patients were included in the study, categorized into two groups: patients with a history of SARS-CoV-2 infection (n = 148) and without prior COVID-19 infection (control group; n = 152). Demographic information, comorbidities, treatments, autoantibodies, cell populations, and cytokines were assessed. A majority of the patients included in this study were female. A high percentage of patients completed the COVID-19 vaccination schedule. The mean age at RA diagnosis was 44.71 years, with most patients presenting with low disease activity. Patients with a history of SARS-CoV-2 infection reported headache, cough, and fatigue more often. A proportion of these symptoms persisted beyond 12 weeks, consistent with PCS. Autoantibody analysis revealed a high seropositivity rate in both groups, with no statistically significant differences related to SARS-CoV-2 infection. Similarly, the evaluation of immune system cell populations showed no significant variations between groups. Cytokine level analysis also demonstrated no statistically significant differences between cases and controls. However, IL-6 data were unavailable for 37% of participants. Long-term follow-up did not demonstrate statistically significant alterations in the immunological profile of RA patients with SARS-CoV-2 infection. Nevertheless, further prospective studies are required to elucidate potential long-term immunological effects in this population.", "url": "https://pubmed.ncbi.nlm.nih.gov/41990050/" } ] }