There were no statistical differences between mean antibody levels in the serum of participants of the HD-COVID-19-positive (50.8 BAURBD-IgG+IgM/mL; n = 9) and RD-COVID-19-positive group (44.1 BAURBD-IgG+IgM/mL; n = 36) before vaccination. This evidence concerns the gene CD40LG and COVID-19.