CD40LG and infection: First, blood samples were screened by colloidal gold-based immunochromatographic assays (GICA) separately detecting IgM and IgG against SARS-CoV-2.22 At a median of 11 months post- infection, only 4% (95% CI, 2–10%) participants returned positive IgM results, which included both positive and weakly positive results, while 62% (95% CI, 54–71%) were IgG positive (Table 1), comparing to 82.2% prevalence of IgM among pre-discharge samples from the same hospital.23 Severe group showed higher prevalence of IgG, while the prevalence of IgM was equally low in both groups (Table 1).