Phase 12 Study to Find the Best Dose and Evaluate Safety and Immune Response of a Chlamydia Trachomatis mRNA Vaccine in Adults Aged 18 to 29

What this Trial Is About

Researchers are evaluating the safety, immune response, and effectiveness of different doses of a Chlamydia messenger RNA mRNA vaccine in adults aged 18 to 29 years. The study includes three initial Sentinel Cohorts to carefully assess safety at low, medium, and high dose levels before expanding to a Main Cohort. The overall goal is to understand how well this vaccine candidate works and its safety profile in young adults. Participants will receive three injections of either a low, medium, or high dose of the Chlamydia mRNA vaccine or a placebo. The injections are given intramuscularly. The study is randomized and placebo-controlled, with multiple groups based on whether participants have prior exposure to Chlamydia trachomatis. The study is designed with stepwise safety assessments in the Sentinel Cohorts followed by evaluation in a larger Main Cohort. During the study, participants will be monitored for immediate reactions up to 30 minutes after vaccination and for side effects up to 12 months following the last injection. Immune responses will be measured through blood tests before and after each vaccine dose. Participants will be followed for about 18 months from the start, including safety monitoring, laboratory tests, and evaluation of immune responses to the vaccine and placebo injections.

Phase 1/2 Study of Chlamydia Trachomatis mRNA Vaccine in Adults Aged 18 to 29 Years