Summary
Typhoid and paratyphoid fever together cause a high burden of disease in low-and-middle-income countries, responsible for up to 21.6 million cases and 216,510 deaths annually. These pathogens are developing resistance to antibiotics, to the point that some infections cannot be treated anymore. Moreover, where enteric fever is endemic, health care providers prescribe antibiotics unnecessarily for any febrile illness, and this practice contributes to the dangerous rise in antibiotic resistance. In this project, we propose to create a novel vaccine against both typhoid and paratyphoid fever that has a realistic path to clinical development and commercialisation, based on an existing vaccine that we improve by combination with a novel component.
Conjugate vaccines against typhoid fever (TCV) have been developed and are being produced by several companies, and will be used to prevent typhoid. However there remains no vaccine to prevent the substantial paratyphoid disease burden in Asia. Importantly, high cost is a limiting factor for wide use of vaccines in low-income countries, therefore a bivalent vaccine targeting both infections would be a particularly suited approach to improving health in the affected areas. Developing a novel bivalent vaccine that incorporates the TCV provides a realistic path to clinical development as compared to a new vaccine composition that has not proven efficacy against typhoid fever yet. We have developed a vaccine against paratyphoid in a previous project, and in this project we propose to combine the new paratyphoid vaccine with a TCV.
Project outcomes
Typhoid and paratyphoid fever together cause a high burden of disease in low-and-middle-income countries, responsible for up to 21.6 million cases and 216,510 deaths annually. Conjugate vaccines against typhoid fever (TCV) have been developed and are being produced by several companies, and will be used to prevent typhoid. However there remains no vaccine to prevent the substantial paratyphoid disease burden in Asia. Importantly, high cost is a limiting factor for wide use of vaccines in low-income countries, therefore a bivalent vaccine targeting both infections would be a particularly suited approach to improving health in the affected areas. We have developed a vaccine against paratyphoid in a previous project, but it is not known if our novel paratyphoid vaccine, based on a viral-vectored formulation, can be mixed or used at the same time as a conjugate vaccine.
In this project we explored that possibility. We combined the new paratyphoid vaccine with a TCV, and, interestingly, demonstrated that both retain their capacity to induce the desired responses. This is an encouraging finding that may open new possibilities in the field of vaccine development against enteric fever but also other diseases.
Dr Christine S Rollier
Associate Professor
Preclinical and Novel Vaccine Development Team
Oxford Vaccine Group, Department of Paediatrics, University of Oxford (UK)
Collaborators:
Dr V Krishna Mohan, Bharat Biotech International Ltd (India)
Prof Andrew J Pollard, Oxford Vaccine Group, Department of Paediatrics, University of Oxford and Children’s Hospital, Oxford (UK)
Dr Christina Dold, Oxford Vaccine Group, Department of Paediatrics, University of Oxford (UK)