Renin-Angiotensin System, SARS-CoV-2 and Hypotheses about Some Adverse Effects Following Vaccination

Coronavirus disease 2019 (COVID-19) affects the lungs but also the cardiovascular system, especially since the spike protein of the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses the angiotensin-converting enzyme 2 (ACE2), existing on the membrane of many cell species, as a receptor. This connection has consequences on the renin-angiotensin system, arterial pressure and coagulation. An imbalance of blood pressure control, of coagulation and platelet functions, and of the kinin-kallicrein system may occur in natural disease but is also partly reflected in some possible negative consequences following vaccination. Knowledge of these mechanisms could help to identify the subjects most at risk of complications and to correctly carry out the causality assessment of adverse events.