New UK and South Africa Variants Confirm Need for Universal SARS Coronavirus Vaccine
DEL MAR, California – December 28, 2020 – Two weeks ago the UK reported a new variant of the SARS-CoV-2 termed VUI 202012/01 and defined by multiple Spike protein mutations (2 deletions and 7 mutations). The rapid spread of the new variant in the UK has prompted many countries to close their borders with the UK pending further analysis of its transmissibility and pathogenicity.
At about the same time another new variant named 501Y.V2 was found in routine surveillance by laboratories in South Africa. This second variant is from a different genetic group (clade GH as opposed to clade GR in the UK) and includes 3 mutations in the receptor binding interface of the Spike protein. A triple mutant at the interface has not been observed before in a large outbreak.
The Spike is used as the antigen for almost all vaccines currently approved or in phase 3 trials around the world. Of particular concern for the two new variants is the mutation N501Y in the receptor binding motif of the Spike protein.
The receptor binding motif is a critical region of the Spike as it is in contact with the host receptor and is also a binding site for neutralizing antibodies elicited by the first generation vaccines. Of further concern is that N501Y appeared simultaneously in different clades and distant locations.
Latest reports from the British and South African governments show that the new variants are spreading much faster than previous strains, with an estimated increase of transmissibility of 56% in the UK and a confirmed second wave of infections in South Africa where this new local variant has become predominant.
The South African variant carries the mutation E484K and six weeks ago another mutation Y453F was observed in mink farms in Denmark. Thus three recent mutations (Y453F, E484K and N501Y) associated with major outbreaks are in the same receptor binding motif and only separated by 30 and 16 amino acids in the Spike protein that contains over 1200 amino acids. Mutations in the receptor binding motif constitute a systemic risk for all vaccines currently approved or in late stage of development.
“These new mutations in the receptor binding motif of the Spike protein confirm the high variability of this region which is used in the antigens of all first-generation vaccines”, according to Pascal Brandys, co-founder and CEO of Phylex BioSciences, a California company that is currently developing a universal SARS coronavirus vaccine.
“Based on analysis of mutations between the SARS-CoV virus of 2003 and SARS-CoV-2 we carefully excluded the receptor binding motif from our antigen. Our universal vaccine should therefore be equally effective against the UK, South Africa and Danish mink variants,” Brandys continued. “We strongly believe that a universal SARS coronavirus vaccine based on highly conserved regions will be the only long term solution for vaccination against a virus that inevitably accumulates mutations over time.”
About Phylex BioSciences
Founded at the beginning of the SARS-CoV-2 pandemic by genomics pioneer Pascal Brandys and coronavirus specialist Jens Herold, Phylex BioSciences is the first company to pursue the development of a universal vaccine against the SARS coronavirus. The result of antigen engineering with conserved epitopes combined with latest generation VLP technology, the vaccine is intended to protect not only against SARS-CoV-2 but also against other virulent strains of the SARS coronavirus to come.
Pascal Brandys, CEO