Mucosal vaccination with adenovirus-vectored and mRNA vaccines against Plague

Summary 

Plague, caused by the Yersinia pestis bacterium and transmitted by fleas, remains a global threat with sporadic but deadly outbreaks occurring in regions including Africa, China, Russia, particularly in the Democratic Republic of the Congo (DRC) and Madagascar. These outbreaks highlight the ongoing risk to public health. Researchers at the Oxford Vaccine Group (OVG) have been at the forefront of developing new vaccines against this ancient pathogen. We used a viral vector (ChAdOx1) carrying protective proteins from the plague bacterium and demonstrated excellent results in preventing plague in mouse models. This vaccine has successfully progressed to human studies, with Phase 1 clinical trials in the UK confirming excellent safety profiles and robust induction of antibody responses. Building on these successes, we are now developing a novel vaccine that uses mRNA technology. As part of this BactiVac project, we aim to test our vaccines as mucosal vaccines to induce strong mucosal responses. The goal is to not only protect against the lung-based (pneumonic) form of plague but also to understand the immune responses — humoral, mucosal, and cell-mediated immune responses that provide the protection. If successful, this research could be a significant step forward in the global fight against plague.