CD8A and myeloid sarcoma: Despite poor antibody responses in most patients with MS treated with aCD20, all of these patients generated robust CD4 and CD8 T cell responses to SARS-CoV-2 mRNA vaccination suggesting that vaccinating B cell-deficient patients is still likely to provide some measure of immunity to SARS-CoV-2, especially considering that T cells may retain recognition of emerging variants of concern that have escaped antibody neutralization40,41.