A T cell epitope-driven
SARS-COV-2 VACCINE
using peptides instead of mRNA
EPV-COV-19
EPV-CoV-19 is a T cell based vaccine designed using the iVAX platform [1]. This first-generation vaccine candidate includes highly conserved T cell epitopes (CD8 and CD4) from SARS-CoV-2.
EPV-CoV-19 is designed to be highly efficacious. Its peptides are both antigenic and immunogenic [2].
This peptide-based vaccine can be adjusted as new variants emerge, and used to boost immune responses or to treat long-COVID.
T cell responses are critical to protection from serious illness and from the sequelae of COVID infection.
Trials of currently approved COVID-19 vaccines demonstrate protection against symptomatic disease after T cell induction and before neutralizing antibodies are observed [3-6].
References are at the bottom of this page.
EpiVax showed that T cell epitope cross-conservation decreased significantly at the time of significant shifts in the Variants of Concern (VOC).
The timeline goes from left to right. "Current" Field strains are compared to four vaccines, shown using the colored lines in the plot. T cell epitope conservation with new strains decreases over time.
Gray-shaded regions highlight time periods with major changes in the predominant circulating strain. Colored arrows show time points of FDA approval/emergency use authorization of each vaccine.
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When T cell epitope cross-conservation of the most recent 'whole antigen (spike) vaccine drops, as compared to emerging VOC, by 5 to 10%, protective efficacy of that vaccine also decreases and the new VOC replaces the previous one.
Adapted from [7].
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IVAX DESIGN PLATFORM
iVAX consists of a suite of immunoinformatics tools for the design of epitope driven vaccines
Emerging and re-emerging infectious diseases represent a significant challenge for next-generation vaccine design and bioterror preparedness. We have composed a suite of online immunoinformatics tools for the accelerated design of proteome-derived, epitope-driven vaccines [1]. Using the Conservatrix algorithm, mutable pathogenic genomes can be probed for highly conserved segments, which are then mapped for T cell epitopes and regions of high epitope density using EpiMatrix and ClustiMer. JanusMatrix (a homology analysis tool for examining pathogen/host sequence similarity with respect to the HLA and TCR faces of an epitope) is used to eliminate sequences which could potentially elicit an undesired autoimmune or regulatory T cell response due to homology with the human genome. Immunogenic Consensus Sequences are created by EpiAssembler, a tool which optimizes the balance between pathogen and population coverage. VaccineCAD links candidate epitopes into a string-of-beads design while minimizing nonspecific junctional epitopes that may be created in the linking process.
With proof of principle established in animal models for vaccines against tularemia, Vaccinia and H. pylori, the iVAX toolkit has become a rapid, efficient, easily accessible and broadly applicable solution for accelerating the development of critically important vaccines for human health and biodefense.