The viral spike protein in grey with the host receptor in red. The Phylex antigen is made of regions of the spike protein close to the receptor. Natural sugars carried by the protein are in blue.
Recent progress in computational analysis allows us to design antigens that are able to elicit neutralizing antibodies, the primary defense against viral infection. These neutralizing antibodies will prevent virus entry into the host cell. The Phylex antigen is based on regions of the viral spike protein close to the host receptor. Our multivalent vaccine is designed to protect not only against SARS-CoV-2, but also against variants in circulation with increased transmissibility, pathogenicity or resistance to first generation vaccines.
We have also developed a recombinant self-assembling nanoparticle platform for our vaccine candidate. This virus-like particle (VLP) displays a large number of copies of our antigen and has a size, geometry and symmetry mimicking the virus. Our antigen is fused to a scaffold element in a single gene construct, and in cell culture the VLP self-assembles and is directly secreted. Alternatively, a messenger RNA translates into the antigen fused to the scaffold element and directs VLP self-assembly in host cells. Thus our self-assembling nanoparticle platform is equally applicable to mRNA or protein vaccines.
In our multivalent vaccine antigens are multiplexed on our self-assembling nanoparticle. The multiplex nanoparticle cross-links B cell receptors to activate B cells, the cells secreting the antibodies, and therefore induces a strong immune response against the wild-type virus and its variants.