Marburg and Ebola hemorrhagic fevers have been described as the most virulent viral diseases known to man due to associative lethality rates of up to 90%. Death can occur within days to weeks of exposure and there is currently no licensed vaccine or therapeutic. Recent evidence suggests an important role for antiviral T cells in conferring protection, but little detailed analysis of this response as driven by a protective vaccine has been reported.
A synthetic polyvalent-filovirus DNA vaccine was developed against Marburg marburgvirus (MARV), Zaire ebolavirus (ZEBOV), and Sudan ebolavirus (SUDV). reclinical efficacy studies were performed in guinea pigs and mice using rodent-adapted viruses, whereas murine T-cell responses were extensively analyzed using a novel modified assay
described herein. Vaccination was highly potent, elicited robust neutralizing antibodies, and completely protected against MARV and ZEBOV challenge. Comprehensive T-cell analysis revealed cytotoxic T lymphocytes (CTLs) of great magnitude, epitopic breadth, and Th1-type marker expression.