Figure 1.

(a) S‐specific antibody responses after the first dose of the BTN162b2 mRNA vaccine against SARS‐CoV‐2. Comparison between infection‐naïve (n = 23, red circles) and convalescent healthcare workers (HCWs) (n = 27, green squares). The latter group included nine individuals without a positive N‐specific serology at inclusion. (b) S‐specific antibody responses after the first dose of the BTN162b2 mRNA vaccine against SARS‐CoV‐2. Comparisons between HCWs with cross‐reactive immunity (CR, red circles), non‐reactive (NR, green squares), convalescent with persistence of antibodies (Cab+, blue triangles) and recovered HCWs with loss of antibodies during follow‐up (Cab−, purple diamonds). Each dot represents an individual after the first dose of vaccine. Lines represent group medians. The dashed line indicates limit of detection (50 AU mL⁻¹). The number of individuals in each group is shown below the graphs.