Dear Editor, We read the article entitled “Vaccinating Patients with Heart Disease Against COVID-19: The Reasons for Priority” with great interest. COVID-19 vaccination is accepted as the best way for preventing the disease, but data on its safety are still warranted. An important problem found after COVID-19 vaccination is the rheological change causing intravascular clotting and thrombotic complications. Changes in blood viscosity after COVID-19 vaccination have been confirmed. A vaccine can induced rapid production of antibody, which is a protein […]