Heat Stable Subunit COVID-19 Vaccine Candidate Generates Rapid Immune Responses in Pre-Clinical Studies

Soligenix, Inc. (Princeton, NJ, USA) has published pre-clinical immunogenicity studies for its CiVax program (heat stable COVID-19 vaccine), demonstrating immunity of both broad-spectrum antibody and cell-mediated, rapid onset immunity is possible using the CoVaccine HT (CoVaccine) adjuvant.

CiVax is the company's heat stable subunit vaccine candidate for the prevention of COVID-19, the infection caused by SARS-CoV-2. The studies conducted by Soligenix in collaboration with the University of Hawaiʻi at Māno and John A. Burns School of Medicine (JABSOM) have demonstrated the feasibility of developing a broadly immunogenic vaccine for COVID-19. The essential attributes of a vaccine successful in controlling the ongoing pandemic are believed to include the ability to rapidly stimulate a balanced antibody response, including an enhanced Th1 response, which includes raising significant virus neutralizing antibodies and potent cell-mediated immunity, demonstrated by T-cell activation. Previous work with the CoVaccine adjuvant has indicated that CoVaccine has these critical characteristics. Soligenix has now demonstrated these attributes of CoVaccine, specifically in the context of SARS-CoV-2. Moreover, these results, using a prototype antigen, also demonstrated a rapid onset of immunity with antibody responses detected within 14 days after the first vaccination.


Subunit vaccines are considered the gold standard for vaccine safety, but are relatively under-represented in fast-tracked COVID-19 vaccine candidates to date. Unlike virally vectored vaccines, there is no limit to the number of times the adjuvant and antigen can be used and the typical safety profile of a subunit vaccine results in a vaccine that is suitable for immune compromised or elderly populations as well.

"Our work to date has demonstrated not only the feasibility of rapid and efficient manufacturing of the required vaccine antigens, but also the potential for a broadly applicable and easily distributed vaccine," said Axel Lehrer, PhD, Assistant Professor in the Department of Tropical Medicine, Medical Microbiology and Pharmacology, JABSOM. "We are delighted with our earlier successes on development of filovirus and flavivirus vaccines with this platform. The results in our latest manuscript confirm that the advantages of our vaccine platform with the CoVaccine adjuvant can also be realized in the context of SARS-CoV-2, while we continue our work to rapidly advance development of a heat stable subunit COVID-19 vaccine in collaboration with Soligenix."

"We believe that creating a vaccine with enhanced stability at elevated temperatures that can obviate the costs and logistical burdens associated with cold chain storage and distribution has the potential to provide a distinct advantage over other COVID-19 vaccines currently in development and simplifies worldwide distribution," said Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. "Our approach appears to be unique in its use of a well-established, well-understood, and safe, subunit platform coupled with a novel adjuvant and a thermostabilizing formulation. We are very encouraged with the latest results and look forward to continuing to advance development of CiVax."

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Soligenix, Inc.