HLA-DRB1 and COVID-19: The antibody titer specific to each of the nine “universal” B-cell epitopes was determined by ELISA in COVID-19 patients infected with multiple SARS-CoV-2 variants of concern (Supplementary Figure S4, left panel) and in vaccinated and mock-vaccinated triple transgenic HLA-A*02:01/HLA-DRB1*01:01-hACE-2 mice challenged with same SARS-CoV-2 VOCs (Supplementary Figure S4, right panel).