CD4 and obesity due to melanocortin 4 receptor deficiency: On the other hand, after adjusting for obesity and other factors, we found no association between DM and antibody or T-cell responses to SARS-CoV-2, except a higher proportion of proliferating CD4 + T cells in DM in responses to ORF 7 and 8 (Fig. 5C, Supplementary Table S2a–f).