Therefore, all of the main factors for the emergence of an auto-immune response can potentially manifest themselves in COVID-19, including molecular mimicry of many SARS-CoV-2 proteins, “Bystander activation”, “Epitope spreading” (in conditions of tissue destruction), breach of the biological barriers in immunoprivileged organs, polyclonal activation of lymphocytes, and pathological activation of APC (as a result of the action of SAg). Here, SAG is linked to COVID-19.