Figure 2. Anti-RBD titers elicited in individuals with or without positives serology at baseline. Antibodies titers in the studied population grouped according to documented absence or presence of previous SARS-CoV-2 infection (defined by positive RT-qPCR, rapid antigen test, or basal anti-RBD titer). Horizontal red lines represent the median. Statistical analyses were performed with Mann-Withney test.