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. 2023 Jan;7(1):100002.
doi: 10.1016/j.rpth.2022.100002. Epub 2022 Nov 25.

SARS-CoV-2 vaccines are not associated with hypercoagulability in apparently healthy people

Lamya Garabet  1   2 , Anna Eriksson  3 , Eirik Tjønnfjord  4 , Xue-Yan Cui  5   6 , Magnus Kringstad Olsen  3 , Hege Karine Jacobsen  3 , Camilla Tøvik Jørgensen  7 , Åse-Berit Mathisen  1 , Marie-Christine Mowinckel  5   6 , Maria Therese Ahlen  8 , Ingvild Hausberg Sørvoll  8 , Kjersti Daae Horvei  8   9 , Siw Leiknes Ernstsen  8 , Ingvild Jenssen Lægreid  8 , Benedicte Stavik  5   6 , René Holst  3 , Per Morten Sandset  5   6   10 , Waleed Ghanima  3   4   10
Affiliations

SARS-CoV-2 vaccines are not associated with hypercoagulability in apparently healthy people

Lamya Garabet et al. Res Pract Thromb Haemost. 2023 Jan.

Abstract

Background: SARS-CoV-2 adenoviral vector DNA vaccines have been linked to the rare but serious thrombotic postvaccine complication vaccine-induced immune thrombotic thrombocytopenia. This has raised concerns regarding the possibility of increased thrombotic risk after any SARS-CoV-2 vaccines.

Objectives: To investigate whether SARS-CoV-2 vaccines cause coagulation activation leading to a hypercoagulable state.

Methods: This observational study included 567 health care personnel; 521 were recruited after the first dose of adenoviral vector ChAdOx1-S (Vaxzevria, AstraZeneca) vaccine and 46 were recruited prospectively before vaccination with a messenger RNA (mRNA) vaccine, either Spikevax (Moderna, n = 38) or Comirnaty (Pfizer-BioNTech, n = 8). In the mRNA group, samples were acquired before and 1 to 2 weeks after vaccination. In addition to the prevaccination samples, 56 unvaccinated blood donors were recruited as controls (total n = 102). Thrombin generation, D-dimer levels, and free tissue factor pathway inhibitor (TFPI) levels were analyzed.

Results: No participant experienced thrombosis, vaccine-induced immune thrombotic thrombocytopenia, or thrombocytopenia (platelet count <100 × 109/L) 1 week to 1 month postvaccination. There was no increase in thrombin generation, D-dimer level, or TFPI level in the ChAdOx1-S vaccine group compared with controls or after the mRNA vaccines compared with baseline values. Eleven of 513 (2.1%) participants vaccinated with ChAdOx1-S had anti-PF4/polyanion antibodies without a concomitant increase in thrombin generation.

Conclusion: In this study, SARS-CoV-2 vaccines were not associated with thrombosis, thrombocytopenia, increased thrombin generation, D-dimer levels, or TFPI levels compared with baseline or unvaccinated controls. These findings argue against the subclinical activation of coagulation post-COVID-19 vaccination.

Keywords: D-dimer; SARS-CoV-2 vaccines; coagulation activation; hypercoagulable state; thrombin generation; thrombocytopenia.

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Figures

Figure
Figure
The mean difference with 95% CI of the difference for the 3 different comparisons PF4, platelet factor 4
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