Covid, and even asymptomatic covid is an endothelial disease.

Polish study Study on endothelial cells shows SARS-CoV-2 disrupts cell elasticity, causing vascular damage even without full replication.

“Clinical data indicate that COVID-19 causes cardiovascular complications, regardless of the severity of the disease. In this work, we have shown that SARS-CoV-2 infection causes vascular dysfunction due to the modification of endothelial cell elasticity.”