The reasons are possibly related to differences in the immunologic response to SARS-CoV-2 infection, a higher concentration of antithrombotic serum factors such as alpha-2-macroglobulin in children, the integrity of vascular endothelium in children, differences in the hemostatic response, and age-related variation in thrombosis risk factors like obesity, cardiovascular disease, smoking, and contraceptives use [18,19]. Here, A2M is linked to obesity due to melanocortin 4 receptor deficiency.