Chlamydia trachomatisvaccine development – a view on the current challenges and how to move forward

INTRODUCTION: is the most common sexually transmitted bacterial pathogen in the world. A licensed vaccine is not yet available, but the first vaccines have entered clinical trials. AREAS COVERED: We describe the progress that has been made in our understanding of the type of immunity that a protective vaccine should induce, and the challenges that vaccine developers face. We also focus on the clinical development of a chlamydia vaccine. The first chlamydia vaccine candidate has now been tested in a clinical phase I trial, and another phase I trial is currently running. We discuss what it will take to continue this development and what future trial setups could look like. EXPERT OPINION: vaccine has been successfully completed. We expect and hope that this will motivate various stakeholders to support further development of chlamydia vaccines in humans.