CD40LG and COVID-19: Concerning working areas, among workers in COVID-19 areas, no RT-PCR positivity was registered with the lowest serological positivity rate (5/325, 1.5%), while the majority of RT-PCR positivity (12/13, 92.3%) and IgM-IgG positivity (34/42, 80.9%) were found in non-COVID-19 dedicated areas (p > 0.05 vs. COVID-19 dedicated areas).