NASVAC has shown the capacity of inducing lymphoproliferative, antibody, T CD8 + ?IFN secreting cell (CTL), T helper (Th1 polarized) and "professional" antigen presenting dendritic cell (DC) responses in mice as well as detectable immune responses against both antigens in healthy volunteers with an excellent safety profile. This novel strategy is based on the inclusion of recombinant particulated HBV surface and core antigens in a novel formulation able to exploit the resources of the mucosal immune compartments of HBV chronically infected patients. Mucosal routes account for appr. 80% of total immunocytes which remains unstimulated with current parenteral immune therapies. A number of extra hepatic compartments are infected by HBV, including tissues associated to secretor organs and mucosal compartments. The secretion of HBeAg and viral particles in saliva and mucosal secretions favors the concept that the virus will not be easily eliminated by parenteral immunotherapy. In addition NASVAC strongly stimulates systemic immunity as previously reported.
It is our hypothesis that NASVAC therapeutic vaccine candidate administered intranasally (IN) in low viral load conditions may subvert tolerance to the surface and core antigens (Ag) of the HBV by inducing specific immune responses in mucosal and systemic compartments and such immune response will favor the control of virus replication.
In addition, current strategies to treat hepatitis B using vaccine therapy are using multiple inoculations of antigens; however the use of syringes remains a problem for health systems in the countries where chronic Hepatitis B is more prevalent. This project is aimed to obtain a non-injectable therapeutic vaccine.
Reference
- Immunology and Cell Biology 2004 Oct;82(5):539-46.
