Initial estimates suggest that front-line HCWs may account for 10–20% of all COVID-19 diagnoses, and subsequent calculations based on meta-analyses of antibody prevalence from several countries demonstrate that the presence of IgG and/or IgM antibodies among HCWs has been found to vary between 7% and 9% [7,8,9,10]. This evidence concerns the gene CD40LG and COVID-19.