Many particulate carrier systems have been demonstrated to be an effective antigen delivery vehicle, with increased levels of intracellular localisation and antigen presentation. Use of particulates in a delivery system can also induce strong immune responses. They are therefore promising candidates for a vaccine delivery system, and may be superior to the commonly used subunit vaccine technology. While synthesis methods using a sacrificial template system such as layer-by-layer have demonstrated potential as an efficient nanocapsule preparation method, there have been no reports of nanocapsules synthesised through the sacrificial templating approach without the use of polymers. We defined the structural and cellular characteristics of such nanocapsules, using the Urease alpha subunit antigen from the human gastric pathogen Helicobacter pylori. Mesoporous silica nanoparticles were fabricated in two distinct size ranges (50 nm and 500 nm) as sacrificial templates by previously established methods1, 2. UreA-based nanocapsules were subsequently synthesised using minimal steps3, with final particles consisting of only the cross-linked protein. UreA nanocapsules were analysed for their structure, their ability to localise intracellularly and their protective efficacy in a mouse model against a Helicobacter pylori challenge. These results highlight the potential of antigen-based nanocapsules as a novel and promising approach to vaccine delivery.