COVID-19: Vaccine-induced immune thrombotic thrombocytopenia

Eur J Haematol. 2022 Dec;109(6):619-632. doi: 10.1111/ejh.13855. Epub 2022 Sep 30.


In late February 2021, a prothrombotic syndrome was encountered for the first time in some of the recipients of ChAdOx1 CoV-19 vaccine (AstraZeneca, University of Oxford, and Serum Institute of India). Since the hallmark of this syndrome is the development of thrombocytopenia and/or thrombosis between 4 and 42 days after receiving a COVID-19 vaccine, it was named vaccine-induced immune thrombotic thrombocytopenia (VITT). Other names include "vaccine-induced prothrombotic immune thrombocytopenia" and "thrombosis with thrombocytopenia syndrome" by the Centers for Disease Control and the Food and Drug Administration (FDA). VITT appears similar to heparin-induced thrombocytopenia in that "platelet activating" autoantibodies are produced in both these conditions due to prior exposure of COVID-19 vaccine and heparin respectively, in turn causing thrombotic complications and consumptive thrombocytopenia. In this article, recent advances in the understanding of pathobiology, clinical features, investigative work-up, and management of VITT are reviewed.

Keywords: COVID-19; VITT; cerebral venous thrombosis.

Publication types

  • Review

MeSH terms

  • COVID-19 Vaccines* / adverse effects
  • COVID-19* / complications
  • Humans
  • Purpura, Thrombocytopenic, Idiopathic* / diagnosis
  • Purpura, Thrombocytopenic, Idiopathic* / etiology
  • Purpura, Thrombocytopenic, Idiopathic* / therapy
  • Thrombocytopenia* / diagnosis
  • Thrombocytopenia* / etiology
  • Thrombosis*
  • Vaccines / adverse effects


  • COVID-19 Vaccines
  • Vaccines