Fig. 2: Deficient memory response of CD8+ T cells of convalescent PASC patients.

Peripheral blood mononuclear cells from non-PASC (n = 65) and PASC (n = 62) individuals were stimulated with N or S viral peptides. Interferon-gamma was quantified by ELISA upon stimulation with N (A) and S (B) peptides for 24 h. All HC were tested, behaving below the detection limit of the technique. A Mann Whitney test was employed to compare the non-PASC and PASC groups. The surface expression of the early activation marker CD69 was evaluated upon 24 hours of stimulation with N (C) and S (D) peptides on CD8+ cells by flow cytometry. Data are shown in a scatter dot plot format as median ± IQR; Kruskal–Wallis test was applied to identify statistical differences followed by Dunn’s multiple comparisons test.