Design and Immunogenicity of SARS-CoV-2 DNA Vaccine Encoding RBD-PVXCP Fusion Protein

Dmitri Dormeshkin; Mikalai Katsin; Maria Stegantseva; Sergey Golenchenko; Michail Shapira; Simon Dubovik; Dzmitry Lutskovich; Anton Kavaleuski; Alexander Meleshko

doi:10.3390/vaccines11061014

Design and Immunogenicity of SARS-CoV-2 DNA Vaccine Encoding RBD-PVXCP Fusion Protein

Vaccines (Basel). 2023 May 23;11(6):1014. doi: 10.3390/vaccines11061014.

Authors

Affiliations

¹ Institute of Bioorganic Chemistry of the National Academy of Sciences of Belarus, 220084 Minsk, Belarus.
² Immunofusion, LLC, 210004 Vitebsk, Belarus.
³ Imunovakcina, UAB, LT-08102 Vilnius, Lithuania.
⁴ Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.

Abstract

The potential of immune-evasive mutation accumulation in the SARS-CoV-2 virus has led to its rapid spread, causing over 600 million confirmed cases and more than 6.5 million confirmed deaths. The huge demand for the rapid development and deployment of low-cost and effective vaccines against emerging variants has renewed interest in DNA vaccine technology. Here, we report the rapid generation and immunological evaluation of novel DNA vaccine candidates against the Wuhan-Hu-1 and Omicron variants based on the RBD protein fused with the Potato virus X coat protein (PVXCP). The delivery of DNA vaccines using electroporation in a two-dose regimen induced high-antibody titers and profound cellular responses in mice. The antibody titers induced against the Omicron variant of the vaccine were sufficient for effective protection against both Omicron and Wuhan-Hu-1 virus infections. The PVXCP protein in the vaccine construct shifted the immune response to the favorable Th1-like type and provided the oligomerization of RBD-PVXCP protein. Naked DNA delivery by needle-free injection allowed us to achieve antibody titers comparable with mRNA-LNP delivery in rabbits. These data identify the RBD-PVXCP DNA vaccine platform as a promising solution for robust and effective SARS-CoV-2 protection, supporting further translational study.

Keywords: COVID-19; DNA vaccine; SARS-CoV-2; receptor binding domain.

Grants and funding

The authors declare that this study received funding from Immunofusion. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article, or the decision to submit it for publication.