ArticleBlood2021
Anti-platelet factor 4 antibodies causing VITT do not cross-react with SARS-CoV-2 spike protein.
Article in Blood, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 84 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
84 citing papers in PubMed, 125 citations in OpenAlex.
- Longitudinal clinical proteomics reveals pneumonia type-specific protein biomarkers and autoantibodies.JCI insight · 2026Article
- Longitudinal clinical proteomics reveals pneumonia type-specific protein biomarkers and autoantibodies.medRxiv : the preprint server for health sciences · 2026Article
- Platelet Membrane Receptors and Signalling Pathways.Handbook of experimental pharmacology · 2026Review
- Review
- Vaxtherapy, a Multiphase Therapeutic Protocol Approach for Longvax, the COVID-19 Vaccine-Induced Disease: Spike Persistence as the Core Culprit and Its Downstream Effects.Diseases (Basel, Switzerland) · 2025Article
- Adenovirus vectors can infect mouse megakaryocytes - implications for vaccine-induced thrombosis/thrombocytopenia.Research and practice in thrombosis and haemostasis · 2025Article
- Prothrombotic antibodies targeting the spike protein's receptor-binding domain in severe COVID-19.Blood · 2025Article
- Vaccine-induced immune thrombotic thrombocytopenia in Tunisia following AstraZeneca COVID-19 vaccination: a case report.The Pan African medical journal · 2025Article
- Autoantibodies to protein S may explain rare cases of coagulopathy following COVID-19 vaccination.Scientific reports · 2024Article
- Vaccine-Induced Immune Thrombotic Thrombocytopenia: Clinicopathologic Features and New Perspectives on Anti-PF4 Antibody-Mediated Disorders.Journal of clinical medicine · 2024Review
- ChAdOx1 nCoV-19 Vaccine and Thrombosis with Thrombocytopenia Syndrome among Adults: A Systematic Review.Advanced pharmaceutical bulletin · 2023Review
- Review
- Thromboembolic Events after COVID-19 Vaccination: An Italian Retrospective Real-World Safety Study.Vaccines · 2023Article
- Vaccine-Induced Immune Thrombocytopenia and Thrombosis (VITT)-Insights from Clinical Cases, In Vitro Studies and Murine Models.Journal of clinical medicine · 2023Review
- Article
- Single cell characteristics of patients with vaccine-related adverse reactions following inactivated COVID-19 vaccination.Human vaccines & immunotherapeutics · 2023Article
- Article
- Article
- Review
- From Immunogen to COVID-19 vaccines: Prospects for the post-pandemic era.Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · 2023Review
24 more citing papers are in PubMed but not listed here.
Corrections and comments
- Commented on by
Authors and funding
27 authors at 11 institutions in 4 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe adverse effect of ChAdOx1 nCoV-19 COVID-19 vaccine (Vaxzevria) and Janssen Ad26.COV2.S COVID-19 vaccine, and it is associated with unusual thrombosis. VITT is caused by anti-platelet factor 4 (PF4) antibodies activating platelets through their FcγRIIa receptors. Antibodies that activate platelets through FcγRIIa receptors have also been identified in patients with COVID-19. These findings raise concern that vaccination-induced antibodies against anti-SARS-CoV-2 spike protein cause thrombosis by cross-reacting with PF4. Immunogenic epitopes of PF4 and SARS-CoV-2 spike protein were compared using in silico prediction tools and 3D modeling. The SARS-CoV-2 spike protein and PF4 share at least 1 similar epitope. Reactivity of purified anti-PF4 antibodies from patients with VITT was tested against recombinant SARS-CoV-2 spike protein. However, none of the affinity-purified anti-PF4 antibodies from 14 patients with VITT cross-reacted with SARS-CoV-2 spike protein. Sera from 222 polymerase chain reaction-confirmed patients with COVID-19 from 5 European centers were tested by PF4-heparin enzyme-linked immunosorbent assays and PF4-dependent platelet activation assays. We found anti-PF4 antibodies in sera from 19 (8.6%) of 222 patients with COVID-19. However, only 4 showed weak to moderate platelet activation in the presence of PF4, and none of those patients developed thrombotic complications. Among 10 (4.5%) of 222 patients who had COVID-19 with thrombosis, none showed PF4-dependent platelet-activating antibodies. In conclusion, antibodies against PF4 induced by vaccination do not cross-react with the SARS-CoV-2 spike protein, indicating that the intended vaccine-induced immune response against SARS-CoV-2 spike protein is not the trigger of VITT. PF4-reactive antibodies found in patients with COVID-19 in this study were not associated with thrombotic complications.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.