Spotlight on vaccine-induced thrombosis and thrombocytopenia (VITT)

Within the first months of the Covid-19 vaccination campaign, previously healthy recipients were identified who developed severe thrombosis (often cerebral and/or splanchnic vasculature) and thrombocytopenia typically after adenoviralvector-based vaccination. Similarities between this syndrome, vaccine-induced thrombocytopenia and thrombosis (VITT), and heparin-induced thrombocytopenia, prompted recognition of the role of anti-platelet factor 4 (PF4) antibodies and management strategies based on intravenous immunoglobulin and non-heparin anticoagulants, which improved outcome. We update current understanding of VITT and potential involvement of anti-PF4 antibodies in thrombotic disorders.