OSC has successfully developed a proprietary manufacturing process for SimCells, achieving an exceptional level of purity. Our SimCells demonstrate a remarkable purity of no viable cells per 1 billion SimCells, as assessed by regrowth assays. This purity level exceeds the NIH guideline for genetically modified organisms by more than an order of magnitude. Using scanning electron microscopy, the SimCell production process was better at preserving cell surface features compared to chemical, thermal, or irradiative bacterial inactivation methods. To assess safety, SimCells were administered to mice via intramuscular, intranasal and intravenous routes. There were no signs of ill health and all animals in all studies exhibited organs of normal size and appearance. Mice administered with E. coli SimCells were found to produce at least 1-log higher levels of E. coli-specific antibodies compared to those receiving UV-irradiated E. coli or vehicle. These in vivo studies highlight the potential of SimCells as effective vaccines against bacterial pathogens. We have extended our SimCell platform to various bacterial species featured on the WHO AMR Priority Pathogens list, including E. coli, P. aeruginosa, Salmonella, and ​Shigella, etc. and are in the progress of developing SimCell vaccines against these pathogens.