The fact that HLA-DRB1*08pos and HLA-DRB1*10pos MS patients are limited to the cohort of those with a disease onset related to SARS-CoV-2 vaccination suggests a possible B cell or antibodies-mediated mechanism(s) probably responsible for initiating or triggering the disease in individuals predisposed to or at risk of developing MS. Here, HLA-DRB1 is linked to myeloid sarcoma.