We next assessed the linear antigenic targets from sera of the six selected COVID-19 patients and five recalled SARS patients using a linear B-cell peptide library spanning the entire S glycoprotein of either SARS-CoV-2 or SARS-CoV, in pools of five overlapping peptides (Fig. 2a, Supplementary Fig. 1). Here, ART4 is linked to severe acute respiratory syndrome.