To explore the potential relationship of SARS-CoV-2 antigenicity with the aberrant expression of HERV-W ENV protein, the levels of IgG, IgM, IgA and IgE against nucleocapsid or spike SARS-CoV-2 proteins were compared across plasma samples showing positive or negative presence of HERV-W ENV in acute and post-COVID-19 condition cases (n=22 and 12 respectively). This evidence concerns the gene CD40LG and COVID-19.