Proportion of subjects with SARS-CoV-2 anti-RBD IgG antibodies seroconversion (seroconversion will be considered as that = 4 times the initial determination of the antibody titer). Measurement time: at 42 (+3 days) with respect to baseline time.

Proportion of subjects with SARS-CoV-2 anti-RBD IgG antibodies seroconversion (seroconversion will be considered as that = 4 times the initial determination of the antibody titer). Measurement time: at 42 (+3 days) with respect to baseline time.