Date: 6/2/2007 8:00:00 AM

SEATTLE, June 2 /PRNewswire-FirstCall/ -- Vical Incorporated (Nasdaq: VICL) today announced the RapidResponse(TM) DNA vaccine platform designed to produce large quantities of vaccine in a matter of days, compared with the several months required for conventional vaccine production. This platform is intended to significantly reduce the time required to develop, manufacture and deploy vaccines against emerging diseases during the early stages of an infectious outbreak. By using a cell-free manufacturing process, the company believes that the RapidResponse(TM) DNA platform can overcome the time, capacity and cost challenges of manufacturing conventional vaccines for diseases such as influenza, which use killed or disabled viruses grown in chicken eggs or via cell culture, requiring months of production time in large, dedicated facilities.

"In an emerging disease outbreak, speed of vaccine deployment is crucial," said Vijay Samant, President and Chief Executive Officer of Vical. "The RapidResponse(TM) DNA vaccine platform has the potential to develop and produce a vaccine against even a previously unknown pathogen within a week of obtaining the pathogen's genetic sequence."

RapidResponse(TM) DNA vaccine manufacturing involves a cell-free process and single-step vaccine purification. The process has the potential to be scaled up by simply using larger equipment with no increase in production time, conceivably allowing production of hundreds of millions of doses of DNA vaccine during the earliest stages of an outbreak. Such speed and scale may be crucial in addressing a potentially pandemic disease such as influenza or severe acute respiratory syndrome (SARS), or an intentional release of a weaponized or bioterrorist-modified pathogen such as anthrax or smallpox.

Data from a study evaluating the RapidResponse(TM) platform were presented by Adrian Vilalta, Ph.D., Vical's Senior Scientific Manager of Immunogen Discovery, at the annual meeting of the American Society of Gene Therapy (Seattle, May 30 - June 3). The initial research was supported by a grant from the U.S. Defense Advanced Research Projects Agency (DARPA). The data demonstrated 100% protection of mice against a lethal challenge with H3N2 influenza after a single 2 mcg dose of DNA vaccine produced by polymerase chain reaction (PCR). Next steps in the development of the RapidResponse(TM) DNA vaccine platform will include determination of the lowest effective dose, head-to-head comparison against plasmid DNA vaccine, and scale-up in adherence with current Good Manufacturing Practices (cGMP) to production of quantities appropriate for initial human clinical trials.

The PCR process produces a small segment of DNA, called a linear expression cassette (LEC), which includes only those DNA sequences essential for the specific vaccine. The bacterial fermentation process typically used for DNA vaccines produces a closed loop of DNA, called a plasmid, which must include DNA sequences required in the manufacturing process. Vical holds patents in the United States and in other key regions based on the company's discovery that administering polynucleotides such as DNA or RNA to tissues, without the use of viral delivery vehicles, may cause expression of the proteins encoded by the polynucleotides. Vical's patent coverage includes delivery of linear DNA as well as plasmid DNA.

"The RapidResponse(TM) DNA vaccine platform may be applicable to a broad range of emerging diseases, and would be of greatest value in rapidly developing vaccines against previously uncharacterized pathogens capable of causing pandemics. The key to the rapid manufacturing is the use of PCR, a well-defined, cell-free process, rather than the cell-based processes used in manufacturing all other types of vaccines," said Dr. Vilalta.

Currently plasmid DNA vaccines, which are under development against pandemic influenza and other infectious diseases at Vical, are manufactured by bacterial fermentation in standardized equipment with a production time measured in weeks rather than months. While plasmid DNA vaccines offer a significant improvement over conventional vaccine manufacturing technologies, the RapidResponse(TM) DNA vaccine platform could offer further advantages.

"We remain excited by the potential of our plasmid DNA vaccines, and we will continue development of these programs because the technology is much closer to commercial realization in humans. But for eventual deployment against future emerging diseases, the RapidResponse(TM) DNA vaccine platform appears to offer significant potential advantages over plasmid DNA vaccines, and vast improvements compared with other current vaccine approaches," Mr. Samant said.

About Vical

Vical researches and develops biopharmaceutical products based on its patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases. Potential applications of the company's DNA delivery technology include DNA vaccines for infectious diseases or cancer, in which the expressed protein is an immunogen; cancer immunotherapeutics, in which the expressed protein is an immune system stimulant; and cardiovascular therapies, in which the expressed protein is an angiogenic growth factor. The company is developing certain infectious disease vaccines and cancer therapeutics internally. In addition, the company collaborates with major pharmaceutical companies and biotechnology companies that give it access to complementary technologies or greater resources. These strategic partnerships provide the company with mutually beneficial opportunities to expand its product pipeline and address significant unmet medical needs. Additional information on Vical is available at http://www.vical.com.

This press release contains forward-looking statements subject to risks and uncertainties that could cause actual results to differ materially from those projected, including: whether the RapidResponse(TM) DNA vaccine platform can overcome the time, capacity and cost challenges of manufacturing conventional vaccines; whether RapidResponse(TM) DNA manufacturing will allow the production of hundreds of millions of doses of DNA vaccines at the earliest stages of an outbreak; whether the RapidResponse(TM) platform will be applicable to a broad range of emerging diseases; whether Vical or others will continue development of the pandemic influenza DNA vaccine candidate; whether strains of avian influenza will emerge as pandemic threats; whether the company's DNA vaccine candidate will be effective in protecting humans against avian influenza; whether the influenza vaccine or any other product candidates will be shown to be safe and effective in clinical trials; the timing, nature and cost of clinical trials; whether Vical or its collaborative partners will seek or gain approval to market the influenza vaccine or any other product candidates; whether Vical or its collaborative partners will succeed in marketing the influenza vaccine or any other product candidates; whether the company's issued patents will be challenged and whether such challenges will have an adverse effect on the scope of the patents; whether the company will enforce its issued patents or will be successful in any enforcement efforts; whether the company will be issued additional patents on the RapidResponse(TM) process or applications; and additional risks set forth in the company's filings with the Securities and Exchange Commission. These forward-looking statements represent the company's judgment as of the date of this release. The company disclaims, however, any intent or obligation to update these forward-looking statements.

    Contacts:  Investors:                         Media:
               Alan R. Engbring                   Susan Neath
               Vical Incorporated                 Porter Novelli Life Sciences
               (858) 646-1127                     (619) 849-6007
               Website:  www.vical.com


SOURCE  Vical Incorporated
    -0-                             06/02/2007
    /CONTACT:  Investors, Alan R. Engbring of Vical Incorporated,
+1-858-646-1127; or Susan Neath of Porter Novelli Life Sciences,
+1-619-849-6007, for Vical Incorporated/
    /Web site:  http://www.vical.com /
    (VICL)

CO:  Vical Incorporated
ST:  California
IN:  HEA BIO MTC
SU:  PDT

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3347 06/02/2007 08:00 EDT http://www.prnewswire.com