Prime-boost malaria vaccine regimen provides sterile protection: Vical

Apr 27 2010

Vical Incorporated (Nasdaq:VICL) announced today that a prime-boost malaria vaccine regimen provided sterile protection, with no disease symptoms and no detectable malaria parasites, in 4 of 15 vaccinated volunteers a full 28 days after challenge with multiple infected-mosquito bites. The remaining 11 vaccinated volunteers and all 6 unvaccinated control volunteers developed parasitic infections. Results were presented at the National Foundation for Infectious Diseases (NFID) Thirteenth Annual Conference on Vaccine Research (Bethesda - April 26-28).

The Phase 1/2a clinical trial evaluated a prime-boost vaccine regimen combining three doses of unadjuvanted two-gene malaria DNA vaccine based on Vical's DNA delivery technology followed by a single dose of a corresponding two-gene viral-vector malaria vaccine. All volunteers were malaria-naive. The vaccines were well-tolerated, and there were no vaccine-related serious adverse reactions. While there was no relationship to antibody titers, three of the four protected volunteers had strong T-cell immune responses to one or both of the encoded malaria antigens. The trial was conducted through the U.S. Military Malaria Vaccine Program, with the participation of the Naval Medical Research Center (NMRC) and the Walter Reed Army Institute of Research, and with financial support from the U.S. Agency for International Development, the Congressionally Directed Medical Research Program and the Military Infectious Diseases Research Program.

Preclinical Vaxfectin^® Results

Separate preclinical malaria vaccine studies, conducted by NMRC, demonstrated that Vical's Vaxfectin^® adjuvant enhanced both antibody and T-cell immune responses to each component of a low-dose, five-gene malaria DNA vaccine. Results were published in the journal Vaccine¹, and support use of the Vaxfectin^® adjuvant in vaccines against complex pathogens such as malaria, in which multiple vaccine components are needed to afford broad protection.

Vical provided the DNA vaccines for the clinical program as well as the Vaxfectin^® adjuvant for the preclinical program.

SOURCE Vical Incorporated