For the development of vaccines Viravaxx exploits the PCFiT technology. It converts immuno-dormant protein epitopes into potent antigens eliciting a strong IgG antibody response. This potential has originally been successfully demonstrated by Biomay AG with the grass pollen allergen Phl p 2.
In order to achieve this remarkable effect immuno-dormant peptides from these protein epitopes are fused to a carrier protein, PreS, originating from HBV. The number of peptide epitopes that can be fused to PreS are virtually unlimited; they can be isolated from different source proteins and can be freely combined.
A generalized structure of these fusion proteins is shown below.
General structure of PreS based peptide carrier fusion proteins
PCFiT is based on the so-called hapten carrier principle, where non-immunogenic haptens (small molecules or short peptides) can be positioned for elicitation of an IgG immune response. In this way, epitopes from coat proteins of the target virus, which in their natural environment are not detected by the immune system, can be made immunogenic. This powerful technology allows to specifically create universal vaccines across different serotypes by addressing invariant regions of the antigen required e.g. for receptor binding and virus entry to target cells.
Biomay AG has developed the PCFiT technology in collaboration with the laboratory of Prof. Valenta at the Medical University of Vienna.