COVID-19, resulting from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)infection, is an unprecedented public health emergency which has directly caused hundreds of thousandsof deaths around the world and put health systems under immense pressure and stretched them beyondtheir capacity. In recent months, massive immunization with newly developed COVID-19 vaccines hasshown promising results towards curbing the spread of COVID-19. However, variants identified indifferent regions have sparked concerns about a potentially diminished vaccine efficacy against thesevariants.Through collaboration with a consortium of academic advisers and our internal scientific intelligence,we have been monitoring the emergence of different SARS-Cov-2 variants worldwide. Consequently,we have generated a library of constructs encoding spike proteins of SARS-CoV-2 carrying definedmutations of projected biological significance, including but not limited to: the UK strain (B.1.1.7),South Africa strain (B.1.351), Brazil strain (P.1) and California strain (Cal.20C). These mutants havebeen further subcloned into expression vectors for two versions of the SRAS-CoV-2 spike protein:• Full-length pre-fusion SARS-CoV-2 spike glycoprotein (S-2P)• RBD-Fc fusion protein of SARS-CoV-2 spike glycoproteinIn addition, our engineered expression vectors contain a variety of tags, facilitating the production oftagged recombinant proteins for research and product development.During the current Stage II of the COVID-19 pandemic during which vaccines have shown promisingresults in containment of the virus spread, we anticipate our COVID-19 Spike Variants Panel willgreatly accelerate research and development in the following areas:• For the characterization of immune reactivities of sera from vaccinated individuals againstvariants;• To be used as probes for isolating and cloning of variant-specific human monoclonal antibodiesfrom infected individuals for development of new therapeutic antibodies;• To be used to generate immune profiles to stratify populations that may require additionalvaccination with variant-specific vaccines;• To be used for the development of surrogate in vitro neutralizing assays based on RBD-ACE2binding;• To further facilitate our understanding between the SARS-CoV-2 spike protein structure andantibody response, for the development of future vaccines with a broader-spectrum of antibodyresponse.At Immune Tech, it is our mission to engage our full capacity, knowledge base, and enthusiasm in oureffort to help combat the novel coronavirus pandemic. We look forward to your comments, suggestions,and collaboration.

COVID-19 Spike Variants Panel