The present invention relates to a complement activating construct comprising a complement factor H-derived short consensus repeat (fH-derived SCR) and a binding molecule which specifically recognizes a pathogen. More specifically, the fH-derived SCR is selected from the group consisting of SCR7, SCR9, SCR13, SCR18-20 and artificial SCR (aSCR). Furthermore, an in vivo method for screening complement-based approaches for the treatment of the prevention, treatment or amelioration of an infection with a pathogen or a pathological condition associated with an infection with a pathogen is described.
