FIG 1.

Design and main seropositivity results of anti-S/RBD SARS-CoV-2 IgG seroprevalence study. Seroprevalence study was carried out in a cohort of 1,121 individuals vaccinated with Sputnik V. First, the humoral immune response of individuals having received one (2 weeks after first dose, n = 122) or two doses (1 to 2 weeks after second dose, n = 999) after the beginning of the vaccination campaign was evaluated. A second seroprevalence study was carried out at 24 weeks after completion of the two-doses vaccination schedule (24 wpv) and included 538 fully vaccinated individuals from the initial cohort. Three hundred and eighty individuals with paired samples obtained both at 2 and 24 wpv were selected for further analysis and divided according to their COVID status (i) without a diagnosis of COVID-19 prior or during the study period (n = 271; Non-COVID); (ii) with confirmed COVID-19 diagnosis prior to the start of the vaccination schedule (COVID-PreV; n = 74); and (iii) with breakthrough infections (confirmed COVID-19 diagnosis between 2 and 24 wpv, COVID-PostV; n = 35). Finally, 49 of these individuals were selected for neutralizing antibodies (Nab) analysis.