However, available DENV-tests are severely affected by ZIKV-antibodies, leading to a large number of false positive test results.20, 31, 32 Recently, ZIKV ELISAs based on NS1-proteins as antigens have been made commercially available, but limitations in IgM and/or IgG detection have been reported.33, 34, 35, 36 Here we present a system for the specific and sensitive serological diagnosis of DENV- and ZIKV infections, based on the E-protein as antigen. This evidence concerns the gene CD40LG and Zika virus infectious disease.