SARS-CoV-2, platelets, and endothelium: coexistence in space and time, or a pernicious ménage à trois?

As we enter year 3 of SARS-CoV-2 pandemic, long-term consequences of COVID-19 have become a major public health issue worldwide; however, the molecular and cellular underpinnings of 'long COVID' remain very poorly understood. A paradigm has recently emerged that thrombo-inflammatory consequences of SARS-CoV-2's impact on endothelial cells and platelets likely play a significant role in the development of chronic symptomatology associated with COVID-19. In this brief overview, we discuss the recent findings pertaining to the detection of SARS-CoV-2 virions in vascular cell subtypes, the contribution of the coagulation system to the development of 'long COVID', and the potential role of stem/progenitor cells in the viral and thrombotic dissemination in this disorder.