( MALAGA Spain May 23 2007 /PRNewswir...)Vical's Vaxfectin Adjuvant With Needle-free Delivery Enhances DNA,Vaccine Performance; Yields Antibody Responses Comparable to,Electroporation Without Tolerability Issues,Health

MALAGA, Spain, May 23, 2007 /PRNewswire-FirstCall/ -- Vical Incorporated today announced that in a recently completed animal study, a DNA vaccine formulated with the company's patented Vaxfectin(TM) adjuvant and delivered by needle-free injection yielded significantly higher antibody responses than an unformulated DNA vaccine delivered by needle and syringe. In a separate animal study, electroporation following injection of unformulated vaccine yielded comparable improvements in antibody responses, but electroporation required anesthesia of the animals while needle-free injection of Vaxfectin(TM)-formulated vaccine was administered safely and tolerably without anesthesia.

"The dose-sparing and immunogenicity-enhancing capabilities of the Vaxfectin(TM) adjuvant have been demonstrated in a range of vaccine applications in various animal models," said Alain P. Rolland, Pharm.D., Ph.D., Vical's Senior Vice President of Product Development, "but the potential safety and tolerability advantages of Vaxfectin(TM) compared with alternative DNA delivery enhancement options are making it our preferred choice for new development projects. We look forward to beginning the initial human testing of a Vaxfectin(TM)-formulated DNA vaccine for pandemic influenza, anticipated in the second half of 2007, and to continued exploration of Vaxfectin(TM)'s use in optimizing efficacy and safety for future prophylactic or therapeutic applications."

Both studies were conducted in rabbits with DNA vaccines encoding cytomegalovirus (CMV) glycoprotein B (gB). The vaccines were either unformulated -- using standard phosphate-buffered saline (PBS) -- or formulated -- using the company's Vaxfectin(TM) adjuvant in PBS. Vaxfectin(TM)-formulated vaccines were injected with a needle-free device. Unformulated vaccines were injected with needle and syringe followed in some animals by electroporation using either a constant voltage multi
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