CD8A and myeloid sarcoma: Overall, we found that PR MS patients develop an Ag+ T cells response which is characterized by higher percentage of Ag+ T cells producing CD107a, a higher percentage of cells CD8+ Ag+ T cells, a higher percentage of Th1 Ag+ CD8+ T cells and lower plasmatic levels of SARS-CoV-2 IgG when compared to RR MS patients and age-matched healthy donors.