In contrast to immune checkpoint inhibitors, endocrine therapy, biologic disease-modifying antirheumatic drugs, or targeted therapies, treatments with anti-CD20 antibodies, Bruton tyrosine kinase inhibitors, Bcl-2 antagonists, anti-CD38 therapy, or antimetabolites have been associated with impaired response to vaccination, as shown in previous studies.11,12,13,14,39 Our study suggests that the immunocompromised patients mostly affected are those with solid organ transplants, followed by patients with autoimmune diseases and hematologic cancers. This evidence concerns the gene CD38 and hematopoietic and lymphoid cell neoplasm.