Fig. 1.

Schematic displaying subjects and samples classified into two cohorts and four subgroups based on their study affiliation and recovered or vaccination status. For this study (rectangular frames), either 110 samples from 76 not-vaccinated subjects with PCR-confirmed SARS-CoV-2 infection (subgroups 1 & 3, highlighted orange) or 312 samples from 305 vaccinated subjects without PCR-confirmed SARS-CoV-2 infection (subgroups 2 & 4, highlighted blue) were considered for subgroups. Details for exclusion from evaluation (dropout, gray bubbles): 27 subjects with a positive PCR-test did not participate in antibody screening; samples from subjects which had a PCR-confirmed SARS-CoV-2 infection and at least one shot of vaccine at date of sample collection; samples from not-vaccinated subjects without PCR-confirmed infection.