In agreement with our results, a previous study assessing the kinetics of mouse IgM antibodies against a recombinant protein from T. gondii sporozoites (SporoSAG), showed a peak of reactivity from 10 to 15 days post-infection in mice infected with oocysts (Doskaya et al., 2014), reinforcing the hypothesis that the use of proteins expressed exclusively by oocysts/sporozoites is critical to identify the early phase of oocyst-driven T. gondii infection. Here, CD40LG is linked to infection.