Tokyo ? DNAVEC Corp., a venture firm based in Tsukuba, Japan, has begun developing a new AIDS vaccine in cooperation with the International AIDS Vaccine Initiative, the world’s largest institution for AIDS study and prevention, sources said Saturday.

The company’s prototype vaccine has been highly effective in animal experiments. DNAVEC plans to improve the product to start clinical tests on humans in about three years.

Though medical institutions worldwide are working on a vaccine for AIDS, none have been developed for practical use. If DNAVEC starts clinical trials, its vaccine will be the first Japanese-made product to enter that stage.

DNAVEC owns the patent for a technology that produces vaccines by inserting part of genes of disease-causing microbes into the Sendai virus, which was discovered in Japan. DNAVEC’s AIDS vaccine can be sprayed into the nose, stimulating several types of immune cells through the mucous membranes in the nasal passages. Another advantage of the vaccine is that it does not adversely affect normal cells in the body, as the vaccine components do not effect human DNA.