Notably, AIM+CD8 T cell vaccine responses were significantly more robust in MS-aCD20 RBD antibody− patients compared to RBD antibody+ patients after the second vaccine dose, supporting the notion that SARS-CoV-2 mRNA vaccine-induced CD8 T cell responses were more vigorous in patients who lacked B cells and antibody responses due to aCD20 treatment. Here, CD8A is linked to myeloid sarcoma.