FIG 3.

Evolution of total anti-Spike/RBD IgG and neutralizing antibody levels against ancestral SARS-CoV-2 after Sputnik V vaccination according to COVID-19 diagnosis. Sera collected at 2 and 24 wpv were obtained from a cohort of 380 individuals at 2 and 24 weeks after completion of the vaccination schedule (wpv) with Sputnik V. Cohort was differentiated into individuals (i) without a diagnosis of COVID-19 prior to vaccination or during the study period (Non-COVID; black dots); (ii) with confirmed COVID-19 diagnosis prior to the start of the vaccination schedule (COVID-PreV; orange dots); and (iii) with confirmed COVID-19 diagnosis after 2wpv (COVID-PostV; purple dots). (A) Anti-Spike/RBD IgG levels were evaluated in Non-COVID (n = 271), COVID-PreV (n = 74), and COVID-PostV (n = 35). Individual PI values and geometric mean with 95%CI are shown. (B) Neutralizing titers (NT) were defined as the highest serum dilution without any viral cytopathic effect on the monolayer using a replicating SARS-CoV-2. NT were evaluated in Non-COVID (n = 29); COVID-PreV (n = 9); and COVID-PostV (n = 9). Individual NT values and geometric mean with 95%CI are shown. Samples with NT below 8 (limit of detection, LOD) were set at 1 to calculate GMNTs. Pie charts illustrate the percentage of samples that resulted positive for neutralizing antibodies (NT ≥ 8). Tables next to each graph indicate the corresponding GM, 95%CI values, and GM fold change of 24 versus 2 wpv. Wilcoxon matched-pair test was used for longitudinal analysis of total IgG antibody levels and neutralizing titers. For nonpaired samples, the Mann-Whitney U test was used. Statistical significance is shown with the following notations: ****, P < 0.0001; ***, P < 0.001; **, P < 0.01; *, P < 0.05; ns, not significant.