Figure 2. Serological profiles based on adapted Shannon diversity index (ASDI) categories.

Recent seasonal influenza virus antigens were used to calculate ASDI per individual to summarize individual antibody profiles in one measure (blue). Assumed cross-reactive antibody responses are depicted in red (ancient- and older pandemic influenza virus strains) and green (avian influenza virus strains). Fluorescence values representing serological reactivity per antigen (x-axis) are shown on a log10-transformed y-axis.