Vaccine

Novel Adjuvant for DNA-Based Vaccine

Application

Adjuvant, capable of boosting the immunogenicity and effectiveness of DNA or MVA-based vaccines.

Key Benefits

Stimulates CD8+ (cytotoxic) T cells directly, which boosts the immune system response against infected cells.
Bypasses the need for CD4+ (helper) T cells to help raise functional CD8+ T cells.
Offers new therapeutic option for creating vaccines against otherwise untreatable diseases.

Technical Summary

The lack of success of DNA or MVA-based vaccines in human clinical trials has refocused researchers on vaccine approaches, capable of increasing both cellular and humoral immunity. Data from human trials using DNA vaccine candidates indicated good CD4+ responses, but a lack of antiviral T cells (CD8) with improved function against the virus. Significant CD8 response is particularly important in designing an effective vaccine because CD8 T cells expand and traffic to infection sites, where they lyse virus-infected host cells.

Dr. Amara and colleagues have discovered a new, potential adjuvant (CD40L) technology able to increase the expression of virus-like particles on the surface. By activating CD8 T cells through cross priming, CD4+ helper T cells are bypassed and CD8+ T cells are stimulated directly. Through increased production of CD8 T cells, the adjuvant demonstrates great value for vaccines activating multiple immunological pathways to fight the disease. In vitro experiments involving Rhesus monkeys, tested a vaccine with the additional adjuvant, and demonstrated heightened activation of the immune system. This data suggests that a DNA or MVA-based vaccine combined with the adjuvant creates a co-stimulatory signal, providing cross priming of T cells in the immune system.