STI Vaccine development
Chlamydia
The world’s most commonly reported bacterial STI, chlamydia is a major cause of infertility.
Despite decades of research and hundreds of studies, no successful chlamydia vaccine has yet been identified. However, promising new tools have emerged in recent years, including technology to genetically manipulate chlamydia. Modeling studies also suggest that a chlamydia vaccine could be cost-effective.
131 million new cases each year
Even when asymptomatic, chlamydia can damage the reproductive system, potentially causing infertility in women
Chlamydia can be cured with antibiotics, but because most people experience no symptoms and tests are often unavailable or unaffordable, it often goes undiagnosed and untreated, leading to onward transmission as well as high rates of reinfection
Statens Serum Institut and Imperial College London published results of a small phase I safety and immunogenicity study in 2019 and recently completed a larger phase I trial.

Next steps identified in the Roadmap include:
Assess Public Health Value
- Obtain better data on the burden of chlamydia-associated infertility, and other adverse consequences, in different settings globally
- Continue to model the theoretical impact of chlamydia vaccines
Facilitate Research and Development
- Continue to advance basic science, translational research and clinical development of chlamydia vaccines
Optimize Global Benefits and Access
- Identify preferred product characteristics to drive development of suitable vaccines for populations who would benefit the most
- Lay the groundwork for fast, targeted rollout of vaccines so they have the greatest impact
Learn More
Luis M. de la Maza, Toni L Darville & Sukumar Pal (2021): Chlamydia trachomatis vaccines for genital infections: where are we and how far is there to go?, Expert Review of Vaccines, DOI: 10.1080/14760584.2021.1899817
Phillips S, Quigley BL, Timms P. Seventy Years of Chlamydia Vaccine Research – Limitations of the Past and Directions for the Future. Front Microbiol. 2019;10:70. doi: 10.3389/fmicb.2019.00070.