CD40LG and COVID-19: Using the cohort of 81 symptomatic individuals with COVID-19 (Table 1), the sensitivity of the SFB assay for IgM detection (32%, 63%, and 92% at a time point of a median of 5 days pio, 10 days pio, and 23 days pio, respectively) and IgA detection (35%, 66%, and 98% at a time point of a median of 5 days pio, 10 days pio, and 23 days pio, respectively) was comparable.