Hawaii Biotech Inc., the state's largest biotechnology company, said one of its dengue vaccine candidates has entered into a Phase 1 clinical study and that it intends to start human trials with its other dengue vaccine within a year.

Hawaii Biotech said the clinical study of its monovalent dengue vaccine has begun at the St. Louis University Vaccine Development Center to determine its safety, dose range and possible side effects. The study is expected to yield results in the next 12 months.

The vaccine is one of several being developed by 'Aiea-based Hawaii Biotech, which uses a unique approach to producing proteins for use as antigens in infectious disease vaccines. Most other companies produce so-called attenuated vaccines, or those produced by finding pathogens that are no longer virulent and can induce a immune response to the disease when injected.

The Hawaii Biotech approach focuses on extracting certain proteins from DNA that are then used to produce the vaccine. The company believes its process is safer than using live viruses and is capable of a rapid scaling of production compared to more traditional means.

Earlier this year, the company successfully completed a Phase 1 trial for its vaccine against West Nile virus, a disease that is carried by birds and spread by mosquitoes. The disease can produce vision loss, paralysis and neurological damage.

The company earlier this month said it had received a three-year $2.9 million grant to develop a vaccine to protect against tick-borne encephalitis. The company said it also hopes to start within the next year a Phase 1 clinical test of its tetravalent vaccine candidate for dengue, a virus that results in severe flu-like symptoms which can evolve into a life-threatening fever.

Dengue infections result in an estimated 20,000 deaths annually, Hawaii Biotech said. Drugs and vaccines typically go through several phases of testing before they can be approved for release to the general public.