Title : A promising novel approach to DNA vaccines
Abstract:
Nucleic acid-based vaccines (mRNA or DNA) present a promising alternative to traditional vaccines due to their ability to induce both humoral and cellular immune responses. While mRNA vaccines have been recognized for their ability to provide efficient protection, concerns remain regarding their safety, durability, and poor thermal stability, reinforcing the need for continued research into alternative nucleic acid vaccine strategies. DNA-based vaccines are well-positioned to address the limitations of current vaccines. However, due to low delivery efficiency, physical delivery devices—such as electroporators or needle-free jet injectors—have been employed for DNA delivery, posing challenges related to user compliance, additional costs, and global accessibility.
Here, we introduce a novel DNA vaccine platform, PlaCCine, designed to overcome the limitations of current vaccines. Its flexible design allows for encoding one or more antigens within a single gene expression plasmid, and its synthetic delivery system eliminates the need for a virus or specialized device. Additionally, it demonstrates thermal stability at practical temperatures, along with a rapid, scalable, and cost-effective manufacturing process. This presentation will highlight the advancements in PlaCCine technology, demonstrating efficacy against various pathogens across multiple species. In a recently completed human clinical trial, a proof-of-concept PlaCCine vaccine targeting a SARS-CoV-2 spike variant was found to be safe and immunogenic following intramuscular administration in healthy participants. Mild to moderate reactogenicity events —primarily tenderness, induration, pain, redness, swelling, and itching at the injection site — were observed but were not dose-dependent and resolved spontaneously. Vaccination with PlaCCine resulted in a dose-dependent increase in neutralizing antibody titers against the variant of concern and subsequent variants. The robust immunogenicity observed in healthy human volunteers, even those previously vaccinated or infected multiple times with the pathogen, underscores the PlaCCine technology platform’s potential to facilitate the development of safe and effective vaccines.
