Given the task definition and input, reply with output. In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

Cutaneous leishmaniasis is a neglected tropical disease caused by the parasite Leishmania and transmitted by sandflies. It has become a major health problem in many tropical and subtropical countries, especially in regions of conflict and political instability. Currently, there are only limited drug treatments and no available licensed vaccine; thus, the need for more therapeutic interventions remains urgent. Previously, a DNA vaccine encoding a 15 kDa sandfly (Phlebotomus papatasi) salivary protein (PpSP15) and recombinant nonpathogenic Leishmania tarentolae secreting PpSP15 have been shown to induce protective immunity against Leishmania major in mice, demonstrating that PpSP15 is a promising vaccine candidate. In this study, we developed a fermentation process in yeast with a yield of~1g PpSP15/L and a scalable purification process consisting of only 2 chromatographic purification steps with high binding capacity for PpSP15, suggesting that PpSP15 can be produced economically. The biophysical/biochemical analysis of the purified PpSP15 indicated that the protein was of high purity (>97%) and conformationally stable between pH 4.4 and 9.0. More importantly, the recombinant protein had a defined structure similar to that of the related PdSP15 from Phlebotomus duboscqi, implying the suitability of the yeast expression system for producing a correctly folded PpSP15. Abbreviations used: CL, cutaneous leishmaniasis; PpSP15, 15 kDa sandfly (P. papatasi) salivary protein; PdSP15, 15 kDa sandfly (P. duboscqi) salivary protein; OD, optical density; DO, dissolved oxygen; BH, bed height; ID, internal diameter; CV, column volume.
Process Characterization and Biophysical Analysis for a Yeast-Expressed Phlebotomus papatasi Salivary Protein (PpSP15) as a Leishmania Vaccine Candidate