IFNB1 and myeloid sarcoma: Here, we broadly interrogate SARS-CoV-2 antigen-specific T and B cells 6 months after the third dose of mRNA vaccine in a cohort of 94 MS patients treated with different DMT such as cladribine, DMF, FTY, IFN-β, natalizumab, teriflunomide or rituximab/ocrelizumab.