Fig. 3

Antibody responses to wild-type SARS-CoV-2 Spike S1 protein of infection-naïve or SARS-CoV-2 (breakthrough)-infected nursing home residents. (a) Boxplots of infection-naïve individuals are shown in red (left) and of infected persons (right) are yellow for an infection before vaccination, light green for an infection between the second and third dose, dark green for an infection between the third and fourth dose, turquoise for an infection between the fourth and fifth dose, blue for an infection shortly after the fifth dose, purple for an infection half a year after the fifth dose, and pink for an infection one year after the fifth dose. Antibody concentrations are expressed in international binding antibody units (BAU) using the 20/136 NIBSC standard and the horizontal dashed line represents the threshold for seropositivity to Spike S1. Data are medians with 75% quartiles and the number of study participants per timepoint and per infection status group are summarized within the graph. (b) A table with median anti-S1 antibody concentrations with interquartile ranges of the NH residents per timepoint and per infection status group. Data in bold are significant. *** p < 0.001, ** p < 0.01, and * p < 0.05