Thrombotic events following Covid-19 vaccines compared to Influenza vaccines

Causal association between COVID-19 vaccination and thrombosis-related biomarkers/thrombosis/ischemic stroke: Mendelian randomization study

BACKGROUND

Observational studies about the association between coronavirus disease 2019 (COVID-19) vaccination and thrombosis/ischemic stroke are inconsistent. The aim of this study is to assess the causality between COVID-19 vaccination and thrombosis-related biomarkers/thrombosis/ischemic stroke using mendelian randomization (MR) analysis.

METHODS

A two-sample MR analysis using publicly available genome-wide association study (GWAS) data was conducted. Causal effects were appraised using inverse variance weighted (IVW, as a primary method), with supplementary methods including constrained maximum likelihood and model averaging, MR-Robust Adjusted Profile Score, MR-Egger regression, simple mode, weighted median, and weighted mode. Sensitivity analyses were conducted using Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis.

RESULTS

Genetically predicted COVID-19 vaccination was negatively associated with C-C motif chemokine 3 [CCL3, odds ratio (OR): 0.694, 95% confidence intervals (CI): 0.484-0.995] and multiple coagulation factor deficiency protein 2 (MCFD2, OR: 0.806, 95% CI: 0.675-0.963). Meanwhile, the IVW analysis revealed significant causal effects between genetically predicted COVID-19 vaccination and ischemic stroke (OR: 1.088, 95% CI: 1.006-1.177), large artery stroke (LAS, OR: 1.251, 95% CI: 1.028-1.521). The leave-one-out analysis revealed that no individual SNP exerted a significant effect on the overall causal estimate.

CONCLUSION

Our study provided evidence supporting a potential causal association of genetically predicted COVID-19 vaccination with CCL3 levels, MCFD2 levels, ischemic stroke risk and LAS risk. These results provide preliminary evidence of potential adverse associations, but further studies are required to fully understand the mechanisms and to validate these findings across broader populations.

Recent Updates on COVID-19 Associated Strokes

The SARS-CoV-2 virus is primarily a respiratory virus, but, as it spread worldwide, it became apparent that there are multiple extrapulmonary manifestations. Reports arose of young and otherwise healthy patients presenting to emergency departments with large-vessel occlusions. Because of a rapidly evolving pandemic, conflicting data sometimes arose regarding the impact of the pandemic on strokes. COVID-19 can induce a hypercoagulable and a proinflammatory state through the interactions with the ACE-2 receptor. These mechanisms may lead to the strokes, both ischemic and hemorrhagic, that are seen in this infection. Strokes, in conjunction with COVID-19 infection, tended to be more disabling and portended a higher mortality. Treatment of these strokes was challenging, as emergency departments were strained with the high burden of COVID-19 admissions. Finally, vaccines against COVID-19 were widely administered, and their potential to cause stroke as an adverse event are discussed. This article will provide an in depth review of the recent updates about the incidence, epidemiology, pathophysiology, clinical presentation and treatment of strokes that are associated with COVID-19.

Target engagement and immunogenicity of an active immunotherapeutic targeting pathological α-synuclein: a phase 1 placebo-controlled trial

Investigational therapeutics that target toxic species of α-synuclein (αSyn) aim to slow down or halt disease progression in patients with Parkinson's disease (PD). Here this 44-week, randomized, placebo-controlled, double-blind, single-center phase 1 study investigated safety, tolerability and immunogenicity of UB-312, an active immunotherapeutic targeting pathological αSyn, in patients with PD. The primary outcome measures were adverse event frequency and change in anti-αSyn antibody titers in blood and cerebrospinal fluid (CSF). Exploratory outcomes were changes in clinical scales and biomarker-based target engagement as measured by seed amplification assays. Twenty patients were randomized 7:3 (UB-312:placebo) into 300/100/100 μg or 300/300/300 μg (weeks 1, 5 and 13) intramuscular prime-boost dose groups. Safety was similar across groups; adverse events were mostly mild and transient. Two patients experienced three serious adverse events in total, one possibly treatment related; all resolved without sequalae. Anti-αSyn antibodies in serum from 12/13 and CSF from 5/13 patients who received three UB-312 doses confirmed immunogenicity. Mean serum titers (in log-dilution factor) increased from baseline by 1.398 and 1.354, and peaked at week 29 at 2.520 and 2.133, for 300/100/100 μg and 300/300/300 μg, respectively. CSF titers were 0 at baseline and were 0.182 and 0.032 at week 21, respectively. Exploratory analyses showed no statistical differences in clinical scales but a significant reduction of αSyn seeds in CSF of a subset of UB-312-treated patients. These data support further UB-312 development. ClinicalTrials.gov: NCT04075318 .

Association between COVID-19 Vaccination (ChAdOx1-S) and Thromboembolic, Thrombocytopenic, Hemorrhagic Events: A Systematic Review and Meta-analysis of Analytical Epidemiological Studies

We conducted a systematic review of analytical epidemiological studies to assess the association between ChAdOx1-S vaccination and thromboembolic, thrombocytopenic, and hemorrhagic events. We searched Medline, Embase, Google Scholar, WHO-COVID-19 database, and medRxiv for studies evaluating the association between ChAdOx1-S and vascular events. Primary outcomes of interest were cerebral venous sinus thrombosis, peripheral venous thrombosis (PVT), and thrombocytopenia. Two independent reviewers screened for eligible studies, extracted data, and assessed the risk of bias. The DerSimonian-Laird random effects model was used to pool the incidence rate ratios (IRRs) separately for the first and second doses. Heterogeneity was assessed using I2 statistics. Twenty studies were included, of which 11 were self-controlled case series, and nine were cohort studies (254 million participants). Pooling of 17 studies showed a higher risk of cerebrovascular thrombosis (IRR = 3.5, 95% CI = 2.2-5.4, I2 = 79%), PVT (IRR = 2.0, 95% CI = 1.1-3.5, I2 = 95%) and thrombocytopenia (IRR = 1.6, 95% CI = 1.4-1.9, I2 = 93%) among those who received ChAdOx1-S vaccination as compared to controls. No increased risk was seen after the second dose or for secondary outcomes. There is moderate-to-high certainty of the evidence for the increased risk of cerebral venous sinus thrombosis, PVT, and thrombocytopenia following the first dose of the ChAdOx1-S vaccine. Systematic Review Registration: PROSPERO CRD42022372768.

[Scope and limitations of teleconsultation during the covid-19 pandemic: accounts from primary healthcare professionals in the Autonomous City of Buenos Aires]

The aim was to explore the scope and limitations of teleconsultation during the pandemic from the perspective of primary care physicians at the Hospital Italiano de Buenos Aires, a private institution located in the Autonomous City of Buenos Aires. A qualitative study was conducted with ten individual semi-structured interviews between January and April 2022. The three major emerging topics were the transition to virtuality, accessibility, and the new care model. Obstacles were related to the massive, forced, and unplanned implementation of teleconsultations. The main benefits included providing care during isolation-distancing and addressing epidemiological doubts. Changes were highlighted in care strategies, consultation frameworks, exchange among colleagues, referral criteria, requests for complementary studies, and in the profiles of those seeking consultations. A misuse of the system by individuals and a trivialization of the consultation moment emerged. The rise of communication and information technologies undoubtedly allowed the continuity of healthcare processes, but it does not replace in-person care, and normative guidelines are needed for its continuity.

Comparison of SARS-CoV-2 Vaccination Skepticism, Reasons, and Concerns Between Mass Vaccination Centers and General Practices in Germany 2021

Introduction

The reluctance to be vaccinated against COVID-19 has significantly curbed vaccine uptake. Unlike mass vaccination centers, general practitioners (GPs) might be able to address some of the patients' concerns through their long-term doctor-patient relationship. This study compared vaccination reasons, concerns and skepticism about vaccination, and perceived importance of the vaccine and its hypothetical value between vaccination centers and GP practices.

Methods

A survey was distributed (07/2021-10/2021) among newly vaccinated individuals in ten GP practices (n = 364) and two vaccine centers (n = 474).

Results

Participants in vaccine centers stated more prosocial and benefit-oriented reasons for vaccination, whereas participants in GP practices more often stated the GP's recommendation as the reason. Perceived importance of the vaccine in combating the pandemic was rated higher among individuals at vaccine centers and with higher health awareness and self-efficacy. Participants at both types of sites who preferred a GP for vaccination expressed more vaccination skepticism, which was also related to older age, more health risk concerns related to COVID-19 vaccines, and lower perceived importance of the vaccine.

Conclusion

Our results indicate opportunities for framing future vaccination campaigns that include vaccination centers. Additionally, a rapid GP involvement in future mass vaccinations might be crucial for overcoming attitudinal barriers and achieving higher vaccine uptake.

Comparison of Venous Thromboembolism Outcomes after COVID-19 and Influenza Vaccinations

Background  Published data on the risk of venous thromboembolism (VTE) with coronavirus disease 2019 (COVID-19) vaccines are scarce and inconclusive, leading to an unmet need for further studies. Methods  A retrospective, multicentered study of adult patients vaccinated for one of the three approved COVID-19 vaccines in the United States of America and a pre-COVID-19 cohort of patients vaccinated for influenza at two institutions: Mayo Clinic Enterprise sites and the Medical College of Wisconsin, looking at rate of VTE over 90 days. VTE was identified by applying validated natural language processing algorithms to relevant imaging studies. Kaplan-Meier curves were used to evaluate rate of VTE and Cox proportional hazard models for incident VTE after vaccinations. Sensitivity analyses were performed for age, sex, outpatient versus inpatient status, and type of COVID-19 vaccine. Results  A total of 911,381 study subjects received COVID-19 vaccine (mean age: 56.8 [standard deviation, SD: 18.3] years, 55.3% females) and 442,612 received influenza vaccine (mean age: 56.5 [SD: 18.3] years, 58.7% females). VTE occurred within 90 days in 1,498 (0.11%) of the total 1,353,993 vaccinations: 882 (0.10%) in the COVID-19 and 616 (0.14%) in the influenza vaccination cohort. After adjusting for confounding variables, there was no difference in VTE event rate after COVID-19 vaccination compared with influenza vaccination (adjusted hazard ratio: 0.95 [95% confidence interval: 0.85-1.05]). No significant difference in VTE rates was observed between the two cohorts on sensitivity analyses. Conclusion  In this large cohort of COVID-19-vaccinated patients, risk of VTE at 90 days was low and no different than a pre-COVID-19 cohort of influenza-vaccinated patients.

New Onset Autoimmune Diseases after the Sputnik Vaccine

The vertiginous advance for identifying the genomic sequence of SARS-CoV-2 allowed the development of a vaccine including mRNA-based vaccines, inactivated viruses, protein subunits, and adenoviral vaccines such as Sputnik. This study aims to report on autoimmune disease manifestations that occurred following COVID-19 Sputnik vaccination. Patients and Methods: A retrospective study was conducted on patients with new-onset autoimmune diseases induced by a post-COVID-19 vaccine between March 2021 and December 2022, in two referral hospitals in Mexico City and Argentina. The study evaluated patients who received the Sputnik vaccine and developed recent-onset autoimmune diseases. Results: Twenty-eight patients developed recent-onset autoimmune diseases after Sputnik vaccine. The median age was 56.9 ± 21.7 years, with 14 females and 14 males. The autoimmune diseases observed were neurological in 13 patients (46%), hematological autoimmune manifestations occurred in 12 patients (42%), with thrombotic disease observed in 10 patients (28%), and autoimmune hemolytic anemia in two patients (7.1%). Rheumatological disorders were present in two patients (7.1%), and endocrine disorders in one patient (3.5%). Principio del formulario Conclusion: Although the COVID-19 Sputnik vaccine is generally safe, it can lead to adverse effects. Thrombosis and Guillain-Barre were the most frequent manifestations observed in our group of patients.

Potential mechanisms of vaccine-induced thrombosis

Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare syndrome characterized by high-titer anti-platelet factor 4 (PF4) antibodies, thrombocytopenia and arterial and venous thrombosis in unusual sites, as cerebral venous sinuses and splanchnic veins. VITT has been described to occur almost exclusively after administration of ChAdOx1 nCoV-19 and Ad26.COV2.S adenovirus vector- based COVID-19 vaccines. Clinical and laboratory features of VITT resemble those of heparin-induced thrombocytopenia (HIT). It has been hypothesized that negatively charged polyadenylated hexone proteins of the AdV vectors could act as heparin to induce the conformational changes of PF4 molecule that lead to the formation of anti-PF4/polyanion antibodies. The anti-PF4 immune response in VITT is fostered by the presence of a proinflammatory milieu, elicited by some impurities found in ChAdOx1 nCoV-19 vaccine, as well as by soluble spike protein resulting from alternative splice events. Anti-PF4 antibodies bind PF4, forming immune complexes which activate platelets, monocytes and granulocytes, resulting in the VITT's immunothrombosis. The reason why only a tiny minority of patents receiving AdV-based COVID-19 vaccines develop VITT is still unknown. It has been hypothesized that individual intrinsic factors, either acquired (i.e., pre-priming of B cells to produce anti-PF4 antibodies by previous contacts with bacteria or viruses) or inherited (i.e., differences in platelet T-cell ubiquitin ligand-2 [TULA-2] expression) can predispose a few subjects to develop VITT. A better knowledge of the mechanistic basis of VITT is essential to improve the safety and the effectiveness of future vaccines and gene therapies using adenovirus vectors.

Acute Arterial Ischemic Stroke Following COVID-19 Vaccination: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Acute arterial ischemic stroke (AIS) has been reported as a rare adverse event following coronavirus disease 2019 (COVID-19) vaccination with messenger RNA (mRNA) or viral vector vaccines. However, data are sparse regarding the risk of postvaccination AIS and its potential association with thrombotic-thrombocytopenia syndrome (TTS).

METHODS

A systematic review and meta-analysis of randomized controlled clinical trials (RCTs), pharmacovigilance registries, registry-based studies, observational cohorts, and case-series was performed with the aim to calculate the following: (1) the pooled proportion of patients presenting with AIS following COVID-19 vaccination; (2) the prevalence of AIS after mRNA and vector-based vaccination; and (3) the proportion of TTS among postvaccination AIS cases. Patient characteristics were assessed as secondary outcomes.

RESULTS

Two RCTs, 3 cohort studies, and 11 registry-based studies comprising 17,481 AIS cases among 782,989,363 COVID-19 vaccinations were included in the meta-analysis. The pooled proportion of AIS following exposure to any COVID-19 vaccine type was 4.7 cases per 100,000 vaccinations (95% CI 2.2-8.1; I 2 = 99.9%). The pooled proportion of AIS following mRNA vaccination (9.2 cases per 100,000 vaccinations; 95% CI 2.5-19.3; I 2 = 99.9%) did not differ compared with adenovirus-based vaccination (2.9 cases per 100,000 vaccinations; 95% CI 0.3-7.8; I 2 = 99.9%). No differences regarding demographics were disclosed between patients with AIS following mRNA-based or vector-based vaccination. The pooled proportion of TTS among postvaccination AIS cases was 3.1% (95% CI 0.7%-7.2%; I 2 = 78.8%).

DISCUSSION

The pooled proportion of AIS following COVID-19 vaccination is comparable with the prevalence of AIS in the general population and much lower than the AIS prevalence among severe acute respiratory syndrome coronavirus 2-infected patients. TTS is very uncommonly reported in patients with AIS following COVID-19 vaccination.

The rationale for the treatment of long-Covid symptoms – A cardiologist's view

The ongoing coronavirus disease 2019 pandemic left us with thousands of patients suffering from neurological, cardiovascular, and psychiatric disorders named post-acute sequelae of COVID-19 or just long-Covid. In parallel, the vaccination campaigns against SARS-CoV-2 spike protein saved millions of lives worldwide but long-Covid symptoms also appeared rarely following vaccination with a strong overlap to the “canonical” long-Covid symptoms. A therapeutic strategy targeting both, post-VAC and post-SARS-CoV-2 long-Covid symptoms is warranted since exposure to the S-protein either by vaccination or SARS-CoV-2 infection may trigger identical immuno-inflammatory cascades resulting in long-Covid symptoms.

Acute ischemic stroke and vaccine-induced immune thrombotic thrombocytopenia post COVID-19 vaccination; a systematic review

INTRODUCTION

One of the rare but potentially serious side effects of COVID-19 vaccination is arterial and venous thrombosis. Acute ischemic stroke (AIS) cases have been reported post COVID-19 vaccination. Herein, we systematically reviewed the reported cases of AIS after COVID-19 vaccination.

METHOD

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. We searched PubMed and Scopus until April 14, 2022 to find studies that reported AIS post COVID-19 vaccination.

RESULTS

We found 447 articles. From those, 140 duplicates were removed. After screening and excluding irrelevant articles, 29 studies (43 patients) were identified to be included. From all cases, 22 patients (51.1%) were diagnosed with AIS associated with Vaccine-induced immune thrombotic thrombocytopenia (VITT). Among AIS associated with VITT group, all received viral vector vaccines except one. The majority of cases with AIS and VITT were female (17 cases, 77.2%) and aged below 60 years (15 cases, 68%). Fourteen patients (32.5%) had additional thrombosis in other sites. Four of them (0.09%) showed concurrent CVST and ischemic stroke. Hemorrhagic transformation following AIS occurred in 7 patients (16.27%). Among 43 patients with AIS, at least 6 patients (14%) died during hospital admission.

CONCLUSION

AIS has been reported as a rare complication within 4 weeks post COVID-19 vaccination, particularly with viral vector vaccines. Health care providers should be familiar with this rare consequence of COVID-19 vaccination in particular in the context of VITT to make a timely diagnosis and appropriate treatment plan.