A needle-free, DNA-based vaccine candidate designed using machine-learning methods has completed a first-in-human Phase 1 study in the UK, with researchers reporting it was well tolerated and induced immune responses against multiple viruses in the sarbecovirus group, which includes SARS-CoV, SARS-CoV-2 and related bat coronaviruses.
Researchers at the University of Cambridge and its spin-out company DIOSynVax reported results from a Phase 1, dose-escalation study of a vaccine candidate known as pEVAC-PS, designed to target conserved features shared across the sarbecovirus group. The trial enrolled 39 healthy adults aged 18 to 50, and vaccinations were carried out at National Institute for Health and Care Research (NIHR) Clinical Research Facilities in Southampton and Cambridge. In the study, the vaccine was administered as plasmid DNA using a needle-free intradermal delivery device that uses a high-velocity micro-fluid jet. Investigators said the primary aim of the first-in-human study was to evaluate safety and tolerability, and reported no significant safety concerns in the small cohort. They also reported immune-response findings consistent with the vaccine’s goal of generating responses that extend beyond a single coronavirus strain, though larger studies are typically required to better quantify breadth and durability. Professor Jonathan Heeney, of the University of Cambridge, said the strategy is intended to shift vaccine development from chasing emerging variants to designing candidates that may better withstand viral evolution. Professor Saul Faust, a Southampton-based investigator involved in the clinical work, said vaccines that target shared features across a virus family could, in principle, improve preparedness for future variants or related viruses. A larger follow-on trial is planned to further assess immune responses in more participants. The University of Cambridge has said the work received support from Innovate UK.
