HLA-DRB1 and COVID-19: HLA-DRβ1*0701 provides a good example of these two differing immunological approaches’ complementarity (no Aotus monkeys having the Aona-DRβ3802 analogue were found in this trial) since 42814 parental peptide had 10/30 COVID-19 recovered human sera reactivity (33.3%) above the threshold level and 42800 9/30 (30%), higher, close to HLA-DRβ*0701 world frequency (22.3 on average, and 25.3% in Caucasians, 27.8% in Asians and 31.7% in Berber populations).