CD40LG and infection: In this study, we analyze a cohort of newborns born to mothers with SARS-CoV-2 infection, for which we determine the infection status, the presence of SARS-CoV-2-specific IgM, IgG and IgA and the count and proportion of lymphocyte and natural killers (NK) subpopulations, and hypothesize a possible influence of the maternal infection status on the newborn immune system.