Figure 2.

Fc-effector functions and neutralization activities induced by mRNA vaccination in SARS-CoV-2-naive and PI individuals

(A) CEM.NKr parental cells were mixed at a 1:1 ratio with CEM.NKr-S cells and were used as target cells. Peripheral blood mononuclear cells (PBMCs) from uninfected donors were used as effector cells in a fluorescence-activated cell sorting (FACS)-based ADCC assay.

(B–J) Neutralizing activity was measured by incubating pseudoviruses bearing SARS-CoV-2 S glycoproteins, with serial dilutions of plasma for 1 h at 37°C before infecting 293T-ACE2 cells. Neutralization half-maximal inhibitory serum dilution (ID₅₀) values were determined using a normalized non-linear regression using GraphPad Prism software.

(A and B, left) Each curve represents the values obtained with the plasma of one donor at every time point. Mean of each group is represented by a bold line.

(A and B, right; C–F) Plasma samples were grouped in different time points (V3, V4, V5, and V6).

(G–J) Neutralization activities against several SARS-CoV-2 variants S were analyzed at the different time points (V3, G; V4, H; V5, I; and V6, J). Naive and PI donors are represented by red and black points, respectively. Undetectable measures are represented as white symbols, and limits of detection are plotted. Error bars indicate means ± SEM. (^∗p < 0.05; ^∗∗p < 0.01; ^∗∗∗p < 0.001; ^∗∗∗∗p < 0.0001; ns, non-significant). For naive donors, n = 20 at V3, V4, and V5 and n = 13 at V6, and for PI donors, n = 11 at V3, V4, and V5 and n = 6 at V6.