Sorrento Announces Its Lead Protein-Based COVID-19 Vaccine Candidate – DYAI-100 – Elicits Strong Neutralizing Immune Responses in Vaccinated Animals Against SARS-CoV-2 and Multiple Major Variants of Concern

Sorrento Therapeutics, Inc. a clinical and commercial stage biopharmaceutical company developing new therapies to treat cancer, pain and COVID-19. The publication details preclinical vaccination studies of a new to-be-licensed and developed protein-based COVID-19 vaccination candidate, DYAI-100. The new RBD-based COVID-19 vaccination candidate demonstrated in preclinical studies the potential to elicit potent neutralizing B-cell immune responses against the original SARS-CoV-2 strain and its emerging variants, including Beta and Delta.

The generation of a protein-based vaccination candidate that provides protection against the original SARS-CoV-2 virus and emerging VoCs has proved to be challenging. The publication reports the protective neutralizing activities of the sera of vaccinated animals against a broad spectrum of SARS-CoV-2 virus and its major VoCs by immunization with recombinant Spike protein receptor binding domain (RBD) administered in conjunction with aluminum-phosphate adjuvant intramuscularly. Immunizing mice with RBD protein vaccine with simple aluminum-phosphate adjuvant led to the production of IgG antibodies recognizing the Spike protein of the prototype SARS-CoV-2 as well as the VoCs, such as Alpha (“United Kingdom”), Beta (“South Africa”), Gamma (“Brazil/Japan”), and Delta (“India”). RBD protein immunization induced to the activation of a Th1 polarization of CD4 positive T cells. Furthermore, RBD protein immunization produced IgG antibodies in vivo, which exerted high neutralizing activity against live SARS-CoV-2 and the highly transmissible VoCs, Beta and Delta, as well as Gamma to a lesser extent. Thus, DYAI-100 represents a promising COVID-19 vaccination candidate against COVID-19 that may potentially offer broad protective range against emerging VOCs of SARS-CoV-2 virus.