This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The long-term goal of this project is to explore the efficacy of vaccine candidates targeting chlamydial infection. Chlamydia trachomatis is a common sexually transmitted disease which is largely asymptomatic, can progress to infertility and has been associated with the facilitated acquisition of other STIs including HIV. The initial phases of this study will focus on determining an appropriate positive control to utilize in future preclinical vaccine studies to be carried out in the macaque model. With the determination of an appropriate positive control, further studies will be conducted in three- to four-arm study designs (test product; positive control; negative control; adjuvant control), where vaccine products can be developed to prevent chlamydial infection and subsequent sequelae.