Development of transmission-blocking vaccines (TBV) is a primary focus with two groups of antigens: surface present antigens (such as Pfs230 and Pfs48/45) and antigens expressed on the zygote and ookinete (such as Pfs25). The N-terminus of Pfs230, named the C-Domain (~443-1132) by Williamson et al has been the subject of primary focus in recent years with demonstrated success both in generation of protein and SMFA results.  We are exploring fragments of this region using bacterial and insect expression systems for the discovery of a transmission-blocking vaccine.