CHMP5 and COVID-19: The second pathway is related to the known pathogenicity of the spike S of SARS-CoV-2 which has been involved in the endotheliopathy and coagulopathy observed in more severe forms of COVID-19: The spike S protein, expressed in both nucleic acid technologies of the COVID-19 vaccines reviewed here, is not only a potent activator of the alternative pathway of complement which may contribute to the endothelial damage observed in COVID-19 patients (59), but also an enhancer of platelet aggregation and thrombus formation (60).