Fig. 1.

Immunothrombosis in natural SARS-CoV-2 infection and vaccine prevention.

A) RNA and DNA SARS-CoV-2 vaccines are not associated with viral replication and systemic RNAaemia or pulmonary vascular territory immunothrombosis as a small nucleic acid inoculums are confined to the muscle and are therefore not linked to innate immune mediated thrombosis. B) Natural SARS-CoV-2 infection is associated with extensive pulmonary capillary, pulmonary arteriolar and pulmonary venular territory immunothrombosis in severe COVID-19. Viral RNA is a potent activation of the coagulation cascade and likely contributes to the immunothrombosis phenotype including arterial and venous territory strokes. Additionally, severe COVID-19 pneumonia appears to be associated with alveolar-capillary barrier breakdown with access of SARS-CoV-2 RNA or RNAaemia which can trigger an innate immune driven venous thrombosis in multiple organs including the brain. So RNAaemia and hypercoagulability from innate immune cell activation within the lung and other factors in severe COVID-19 pneumonia may predispose to venous territory strokes. Although HIT may also exhibit arterial and venous strokes it has a distinct autoimmune component.