SARS-CoV-2 specific IgA seems to be a high performing early diagnostic endpoint (Ma et al., 2020; Sterlin et al., 2021), while the kinetics of post-infection IgM and IgG better reflect peak and waning immunity in convalescent cohorts (Bichara et al., 2021; Duysburgh et al., 2021; De Greef et al., 2021). This evidence concerns the gene CD40LG and infection.