SP1 and Huntington disease: Our laboratory, specialized in the B-cell dysregulation in IEI, enabled us to apply our knowledge of B-cell biology through multiparametric flow cytometry (15) to analyze the specific B cells generated by natural SARS-CoV-2 infection and after immunization with the SARS-CoV-2 mRNA vaccine (BNT162b2/Pfizer) in HD and patients with IEI, together with routine well-standardized techniques such as EliA SARS-CoV-2-Sp1 IgG and QuantiFERON SARS-CoV-2.