Development of a needle-free, high-density microarray patch (HD-MAP) delivering a typhoid conjugate vaccine (Vi-DT), to improve access to, and effectiveness of, Vi-DT

Vaxxas and SK bioscience aim to generate data to demonstrate that further clinical development of Vi-DT HD-MAPs is warranted. This would be in the form of immunogenicity data in humans, thermostability data, and an initial analysis of the potential value of Vi-DT HD-MAPs in the control of typhoid. The project would be the first step towards the longer term goal of market authorisation and WHO prequalification (PQ) of Vi-DT HD-MAPs, which we believe could significantly improve access to Vi-DT in LMICs and reduce the total-system-cost of immunisation. Subsequent clinical development of Vi-DT HD-MAPs could proceed rapidly, through Phase 2 and 3 trials, following the development pathway used by SK bioscience for the Vi-DT injectable vaccine. In the longer term, HD-MAPs could be developed to deliver novel vaccine combinations, such as: HD-MAPs delivering Vi-DT and paratyphoid and/or non-typhoidal Salmonella vaccines. Finally, the Phase 1 trial in this project is expected to be the first clinical trial of any MAP delivering a polysaccharide–protein conjugate vaccine (PS-PCV), an important class of vaccines that includes pneumococcal and meningococcal vaccines. The project, therefore, should help advance use of MAPs as a vaccine-technology platform for the delivery of vaccines highly valued in LMICs.