The viral spike protein in grey with the host receptor in red. The Phylex antigen is made of conserved 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 conserved regions of the viral spike protein in all SARS coronaviruses. Therefore our universal vaccine is designed to protect not only against SARS-CoV-2, but also against other virulent strains of the SARS coronavirus that are likely to appear in the future.
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.
After inoculation the VLPs travel rapidly to lymph nodes, cross-link B cell receptors to activate B cells, the cells secreting the antibodies, and therefore induce a strong immune response.