Bar-Ilan Univ. researchers on road to COVID-19 passive vaccine

A team of Israeli researchers at Bar-Ilan University have identified short amino acid sequences - often referred to as the “building blocks of life” - that could help develop a vaccine against the novel coronavirus and which they believe could stop the next outbreak.

“Our study has identified a set of potential immunodominant epitopes from the SARS-CoV-2 proteome, such that these epitopes are capable of generating both antibody and cell-mediated immune responses,” Dr. Milana Frenkel-Morgenstern, head of the Cancer Genomics and BioComputing of Complex Diseases Lab at Bar-Ilan University’s Azrieli Faculty of Medicine, explained.

Epitopes, known also as antigenic determinants, are the part of the antigen that binds to a specific antigen receptor on the surface of B cells or T cells. They are capable of stimulating an immune response.

Immune responses that are based on specific immunodominant epitopes involve the generation of both antibodyand cell-mediated immunity against pathogens presenting such epitopes. Such immunity can facilitate fast and effective elimination of the pathogen.

The result: A passive (as opposed to an active) vaccine, capable of activating both cellular and humoral immune responses in humans.

During this study, Frenkel-Morgenstern said, the team mapped coronavirus epitopes with influenza virus epitopes available in the Immune Epitope Database (IEDB) and found that few influenza virus epitopes share more than 85% sequence identity with severe acute respiratory syndrome-related coronavirus (SARS-CoV) experimentally detected epitopes.

“Therefore, we looked for other known viruses that may have experimentally confirmed epitopes,” the researcher explained. “In the present research, we used an immunoinformatics-based extensive computational approach to mine the proteome of SARSCoV-2 and subsequently identify immunodominant epitopes of SARS-CoV-2. Detecting immune responses that are based on specific immunodominant epitopes enables generating both antibody-mediated and cell-mediated immunity against a certain pathogen. This can facilitate the fast and effective elimination of the pathogen.”

Of the 25 epitopes that were discovered to be 100% identical to SARS, seven are potentially effective vaccine candidates, and the research shows these epitopes could cover as much as 87% of the worldwide population. Further, analysis revealed that the epitopes are non-allergic and non-toxic to humans and have very low risk for generating autoimmune responses.

Now, she said that her team is looking for partners and companies to build the vaccine constructs and test it in-vitro, on animal models and then through clinical trials.

She said the process would take at least six to 12 months.

The research was published in the journal MDPI Vaccines.