Single Injection of Vical's Avian Flu DNA Vaccine Provides 100% Protection in Ferrets


VIENNA, Austria, Oct. 20 /PRNewswire-FirstCall/ -- Vical Incorporated (Nasdaq: VICL) today announced that a single injection of the company's lead avian influenza (flu) DNA vaccine candidate provided 100% protection in ferrets against lethal challenge with a highly virulent H5N1 virus (Vietnam/1203/2004). Conventional vaccines under development for avian flu typically have required two or more doses in humans, even with novel adjuvants, to produce the immunogenicity levels expected to provide protection.

The company had previously demonstrated that two doses of the vaccine candidate provided 100% protection in mice and ferrets against lethal challenges with H5N1 virus. A single-dose vaccine regimen could prove beneficial during a pandemic, both in extending vaccine supply to protect a greater number of people, and in achieving protective immune responses as quickly as possible. The studies were part of the company's program to develop a DNA vaccine to protect humans against emerging strains of flu virus that have the potential to cause a pandemic. Vical's three-component DNA vaccine candidate encodes two highly-conserved influenza virus proteins -- nucleoprotein (NP) and ion channel protein (M2) -- plus the H5 avian influenza virus surface protein, and is formulated with the company's patented Vaxfectin(TM) adjuvant.

"We are excited by the recent advances in our pandemic flu vaccine development program," said Vijay B. Samant, President and Chief Executive Officer of Vical. "Earlier this week, we presented data from mouse studies demonstrating the dose-sparing ability of our Vaxfectin(TM) adjuvant when used with conventional flu vaccines. Today we presented data from ferret studies demonstrating the ability to provide complete protection with a single dose of our Vaxfectin(TM)-formulated avian flu DNA vaccine. Our goal is to advance into human testing with this program as quickly as possible, both to provide a potential defense against a pandemic outbreak and to explore the potential for a seasonal flu vaccine using a similar approach."

Larry R. Smith, Ph.D., the company's Vice President of Vaccine Research, presented the data Friday at the annual meeting of the Second International Conference on Influenza Vaccines for the World (Vienna, October 18 - 20). Financial support was provided under previously-announced grants from the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH). All lethal challenge testing was conducted in BSL-3 facilities at St. Jude Children's Research Hospital under the direction of Richard J. Webby, Ph.D.