CD40LG and tick-borne encephalitis: Some patients developed mostly IgM antibodies specific for the infecting dengue serotype (e.g., Figure 2a sample D6, Figure 2b sample D10, Figure 2c sample D1) with no detectable cross-reactivity, similar to what was seen in Zika and TBE patients (Figure 1a,b); others developed more and different specificities of cross-reactive antibodies (e.g., Figure 2a sample D5, Figure 2e).