Built on success in evaluating the wheat germ-expressed Pfs230 domains, recombinant Pfs230 domains were also expressed in P. pastoris and E. coli. Antisera raised against these domains demonstrated potent transmission blocking activities in an ex vivo standard membrane feeding assay, in a complement-dependent manner. Multiple expression clones were evaluated for their recombinant Pfs230 production yield and induction of functional antibodies. A Pichia expression clone was selected, and cGMP grade recombinant Pfs230 was manufactured. The current efforts are focused on generating cGMP grade Pfs230-EPA, to be combined with Pfs25-EPA vaccine and tested in humans as potentially effective transmission blocking vaccine.