For example, the COVID-19 IgG/IgM Rapid Test Cassette kit from Orient Gene Biotech can detect IgM/IgG with a sensitivity up to 95.8%,147 and the Onsite CTK Biotech COVID-19 split IgG/IgM Rapid Test (CTK Biotech, Poway, CA, USA) was able to diagnose COVID-19 with sensitivity and specificity of 88.2% and 94.0%, respectively.148 However, in most publications, a satisfying sensitivity of LFA was only occurred after at least one week of the infection due to the low concentration of both IgG and IgM in the first weeks. Here, CD40LG is linked to infection.