3 December 2020 - - US-based vaccine biotechnology company Ufovax, LLC has extended its intellectual property portfolio to include an exclusive global license to a patent covering the design of an optimized antigen for SARS-CoV-2, the company said.

The patent, entitled Stabilized Coronavirus Spike (S) Protein Immunogens and Related Vaccines, was filed by Scripps Research on June 29th of this year and was allowed by the US Patent and Trademark Office (USPTO) on Nov 24, 2020.

Described earlier this year in a submission available on the bioRxiv preprint server, a systematic study of five antigen designs was completed along with evaluation of vaccine response in mice.

Using the popular S2P mutation of the Spike alone, the optimized spike antigen design (S2GΔHR2) alone and the S2GΔHR2 displayed on three different SApNPs in a comparison study, the S2GΔHR2-presenting I3-01v9 1c-SApNP vaccine candidate elicited the strongest neutralizing antibody response (7-fold higher than S2P alone).

In another study described in the same submission, the SApNP presenting this optimized spike antigen was also shown to elicit a positive TH1 profile in mice.

The now-patented optimized spike has several distinguishing features. In addition to replacing the double proline mutation in heptad repeat 1 with a double glycine mutation and substituting several amino acid residues of the S1/S2 cleavage site, this spike is purposefully missing the highly flexible heptad repeat 2 stalk.

As reported in several independent publications, the HR2 stalk is part of the fusion core and causes random spike orientations on the virion surface. Zhu and his team therefore consider this to be a major cause of spike metastability.

According to Zhu, who co-founded Ufovax, this metastability is partly responsible for masking the COVID-19 spike from immune recognition and allowing very efficient human infection.

Ufovax is a privately held biotechnology company currently focused on the development of protein nanoparticle vaccines for infectious diseases and has a pipeline of eight additional vaccines in pre-clinical development.