Vical Incorporated announced that the company has been requested to manufacture clinical-grade supplies of an experimental DNA vaccine against the West Nile Virus for development planned by the Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH). The new West Nile Virus vaccine manufacturing agreement is in addition to Vical's large-scale DNA vaccine manufacturing subcontract announced in May 2003, and Vical's Ebola DNA vaccine manufacturing subcontract announced in July 2002; all of the contracts are issued and managed on behalf of NIAID's Vaccine Research Center by SAIC Frederick Inc under the umbrella of a federally funded prime contract with NIH.

Vical's President and Chief Executive Officer, Vijay B. Samant, said, "Vical's DNA delivery technology offers a unique opportunity to shorten vaccine development timelines. The 'plug and play' nature of our gene delivery method allows rapid evaluation of candidate immunogens, which can cut years from the total vaccine development cycle. We already have begun production of the West Nile Virus vaccine under this new agreement. Another benefit of using Vical's technology platform for such virulent agents is that development and production of vaccines do not involve any handling of the pathogen itself. These speed and safety advantages are extremely important for emerging diseases such as West Nile Virus, Ebola, SARS and others, which can spread rapidly if unchecked by either natural or conferred immunity. DNA vaccines for a wide variety of infectious diseases are under development by Vical, its licensees, and others.

"Through this collaboration, our technology has the potential to yield the first approvable human vaccine for West Nile Virus. The vaccine construct incorporates West Nile Virus gene sequences known to be immunogenic. We are pleased to apply our expertise and manufacturing resources in support of the VRC's West Nile Virus vaccine program, and we look forward to the development of an effective vaccine against this emerging disease."

West Nile Virus has been an increasing seasonal threat in the United States over the past several years, causing growing numbers of cases and deaths in birds, horses, and humans each summer. The disease is spread by many species of mosquitoes, which carry the virus from host to host. Most infected people have no disease symptoms, and some have only mild symptoms. But approximately one out of every 150 infected people develops serious disease symptoms of the central nervous system, including headache, high fever, tremors, convulsions, numbness, vision loss, coma, and paralysis lasting several days to several weeks, potentially with some permanent neurological damage. Most West Nile Virus deaths are caused by encephalitis, a severe swelling of the brain, or meningitis, a severe swelling of the membrane surrounding the brain and spinal cord.

Conventional vaccines, using whole killed West Nile Virus, are available for horses and for some species of birds. To develop a human vaccine using this approach, however, could require many years of further development and testing to provide sufficient proof of safety and effectiveness.