Figure 5.

Binding and neutralizing antibody levels stratified by age of serum donors. The binding antibody levels (A) as in Figure 2 and the neutralizing antibody levels (B) as in Figure 3 were stratified by the age of the serum donors and divided in three groups: below 40 years of age (n=46), 40 to 60 years of age (n=87) and older than 60 years of age (n=76). The color guide for (A, B) is shown in the top right corner. Each dot represents one individual sample. The dashed line in (B) indicates the detection limit. Statistically significant differences in antibody levels compared to the age group “< 40 years” are indicated by asterisks (* p < 0.05; ** p < 0.01, *** p < 0.001, **** p < 0.0001; Kruskal-Wallis one-way ANOVA on ranks and Dunn’s multiple comparisons test).