As we and others have described for primary vaccination [4,5,6], responses to vd3 and vd4 with monovalent vaccine were inferior in some MM groups compared to healthy individuals: Patients with MGUS, progressed MM stage with anti-CD38 mAb, and MM after SCT with IT mounted low and fast-waning IgG levels against hu-1 and Omicron strains without significant neutralisation capacity against VOCs. Here, CD38 is linked to Miyoshi myopathy.