Vical Pandemic Influenza Vaccine Demonstrates Cross-reactivity Against California, Texas and Mexico H1N1 Strains

Vical Pandemic Influenza Vaccine Demonstrates Cross-reactivity Against California, Texas and Mexico H1N1 Strains 

SAN DIEGO, Sept. 10, 2009 (GLOBE NEWSWIRE) -- Vical Incorporated (Nasdaq:VICL) announced today that the company's DNA vaccine against A/H1N1 pandemic influenza (swine flu) has demonstrated robust immune responses in 100% of vaccinated animals against virus strains isolated from recent outbreaks in three distinct geographic locations -- California, Texas and Mexico.

Vical's plasmid DNA vaccine contains the H1 hemagglutinin gene sequence provided by the U.S. Centers for Disease Control and Prevention (CDC) for the swine-origin A/California/04/09 pandemic influenza virus, and after two doses produced immune responses well above the accepted protection threshold in 100% of vaccinated mice and rabbits using HI assays against the swine-origin A/California/07/09 x-179a, A/Texas/15/09 and A/Mexico/4108/09 influenza viruses. Hemagglutination inhibition (HI) titers were well above the protection threshold of 40, ranging from 320 to 2,560 in mice, and from 640 to 2,560 in rabbits against the California strain. Results against the Texas and Mexico strains were essentially equivalent, ranging from 640 to 2,560 in both mice and rabbits. Vical's vaccine would also be expected to provide similar robust immune responses against other swine-origin A/H1N1 influenza virus subtypes, supporting selection of a single A/H1N1 virus strain as the basis for the vaccine.

"Cross-reactivity is consistent with previous CDC reports that circulating strains of swine-origin A/H1N1 pandemic influenza have remained antigenically homogeneous," said Vijay B. Samant, President and Chief Executive Officer of Vical, "but future viral changes are unpredictable and could be far more substantial. The inherent speed of our DNA vaccine platform both in initial development and manufacturing could be extremely important in addressing the potential shortfalls of conventional vaccine approaches."

Vical has entered into a Cooperative Research and Development Agreement (CRADA) with the U.S. Naval Medical Research Center (NMRC), a biomedical research organization within the U.S. Navy, to develop a vaccine against H1N1 influenza.

"We are working with the U.S. Navy to secure funding to advance our H1 vaccine into human clinical testing," added Mr. Samant. "Based on the sustained threat from the ongoing H1N1 pandemic, we have initiated critical-path manufacturing activities to allow initiation of a Phase 1 trial in as little as four to six weeks after funding is secured."

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

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This press release contains forward-looking statements subject to risks and uncertainties that could cause actual results to differ materially from those projected. Forward-looking statements include statements about Vical's vaccine technologies and their potential application in a vaccine against H1N1 influenza, potential human clinical testing of such a vaccine, the Vical/NMRC CRADA, potential changes in circulating strains of influenza, potential government regulatory and procurement activities, as well as the company's focus, collaborative partners, and product candidates. Risks and uncertainties include whether the company's technologies will be successfully applied for the development of an H1 DNA vaccine; whether such vaccine will advance to clinical testing quickly, if at all; whether funding will be secured to support a Phase 1 trial; whether Vical, NMRC or others will continue development of any influenza DNA vaccine candidates; whether Vical and/or NMRC will terminate the CRADA before achievement of its objectives; whether the company's DNA vaccine candidate will be effective in protecting humans against H1N1 or any other strains of influenza; whether H1N1 pandemic influenza will undergo substantial strain changes; whether Vical's pandemic influenza vaccine will advance sufficiently to be considered for licensure during future pandemics; whether results in animal testing will be predictive of results in human testing; whether any product candidates will be shown to be safe and effective; the timing, nature and cost of clinical trials; whether Vical or its collaborative partners will seek or gain approval to market any product candidates; whether Vical or its collaborative partners will succeed in marketing any product candidates; 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.

CONTACT: Vical Incorporated
         Alan R. Engbring
         (858) 646-1127