Antibodies from malaria-exposed pregnant PNG women mediated significantly higher levels of complement C1q (Fig. 1A) and C3 (Fig. 1B) fixation to the surface of CS2 pRBCs, compared to malaria non-exposed control donors (both P<0.001) (characteristics of the 302 women included in this study data are shown in Table 1). Here, C3 is linked to malaria.