Abera Bioscience AB
Abera Bioscience has developed a proprietary platform for the rapid development of multivalent and multistage vaccines. The platform makes use of Outer Membrane Vesicles (OMVs) that display several antigens from the same or different microorganisms at high density at their surface, and is suitable for the production of combination-vaccines targeting multiple diseases or variations of the same disease simultaneously.
OMVs are small vesicles that naturally shed from the outer membrane of both harmless and pathogenic bacteria. OMVs are highly promising vaccine candidates
because they combine several unique features:
• Immunogenicity: they have intrinsic adjuvant activity, similar to the parent bacteria they are derived from, resulting in strong stimulation of both humoral and cellular immune responses.
• Safety: unlike the parent bacteria, OMVs cannot replicate and are thus not subject to the regulatory hurdles that complicate the introduction of live, replicating bacteria as vaccines.
• Compatibility with oral and nasal delivery: ideally suited to induce not only systemic but also local mucosal responses to prevent transmission of pathogens.
Of note, OMVs are already used in licensed human vaccines such as the recently approved MenB vaccine.
Abera brings the OMV technology to the next level by decorating them with antigens from other (disease causing) bacteria, viruses or parasites. To this end, we have adapted a natural system for bacterial protein secretion (Autotransport) into the most efficient and versatile system for surface display of antigens known today. This way of presenting antigens has the following additional advantages:
• Optimal exposure to the immune system.
• Compatible with simultaneous expression of various sizeable antigens to elicit broad protection (even to more than one pathogen) and to prevent immune evasion.
• Acceleration of development: prototype vaccines can be ready in days rather than months.
• Scalable, cost-effective production methods based on a novel hypervesiculating bacterial strain made by Abera.
Prototype vaccines were shown to elicit strong humoral and cellular responses in both mice and cell-based assays and protection against infection in challenge experiments in mice. Other technologies – all based on Abera’s unique expertise in Autotransport – include the display of antigens on the surface of living bacterial cells (15000 to 150000 copies per cell depending on the complexity of the construct) and the secretion of antigens into bacterial culture medium. These technologies enable the development of antigen selection methods and the construction of live and subunit vaccines for specific (also therapeutic) applications.
Abera technology: antigens are produced inside bacteria and efficiently displayed on the surface of living cells or non- living OMVs.
Alternatively, antigens can be secreted into the extracellular environment for easy recovery.