Such antibodies do not disappear even after the response reaches its highest point (3‐4 weeks post‐infection) and thus, can be identified over longer duration of time (up to several years); quite conversely, despite the swift induction of IgM antibodies (2–3 weeks after exposure), they linger merely for a few months (Godfroid et al., 2002; Saegerman et al., 2004; Sutherland, 1984). Here, CD40LG is linked to infection.