Fig. 2: Spike-specific antibody response following SARS-CoV-2 mRNA vaccination.

a Anti-spike IgG detected at pre v1, pre v2, +30 v2, +60 v2, and +150 v2 in plasma of PLWHIV. Data are presented as box and whiskers diagram showing the minimum and maximum of all the data. Kruskal–Wallis test, followed by Dunn’s post test for multiple comparisons, was used for assessing statistical differences between groups. *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001. b Time course of spike-specific IgG response in PLWHIV and HC. Antibody titers are expressed as the reciprocal of the dilution of sample reporting a double OD value compared to the background. Data are presented as geometric mean titers (GMT) with 95% CI. Mann–Whitney test was used for assessing statistical differences between groups at each time point. c, d Surrogate virus neutralization assay (sVN) performed at +60 v2 and +150 v2. In c, data are reported as ACE2/RBD binding inhibition percentage with box and whiskers diagram showing the minimum and maximum of all the data. A threshold (dotted red line) was placed at 30% inhibition percentage to discriminate between positive and negative samples. Kruskal–Wallis test, followed by Dunn’s post-test for multiple comparisons, was used for assessing statistical differences between groups. The percentage of positive subjects over all samples, tested at each time point, is reported in d. Fisher’s Exact Test was used to assessing statistical differences between groups. *P ≤ 0.05; **P ≤ 0.01. Sample size PLWHIV: pre v1 (n = 54), pre v2 (n = 38), +30 v2 (n = 53), +60 v2 (n = 51), +150 v2 (n = 22). Sample size HCs: pre v1 (n = 25), pre v2 (n = 50), +30 v2 (n = 52), +60 v2 (n = 75), +150 v2 (n = 69). All samples were biologically independent.