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TOKYO, March 10 (Reuters) - A group of Japanese researchers has developed a substance that could potentially help make flu vaccines effective for multiple strains of the disease, including strains of the bird flu virus, Japan's National Institute of Infectious Diseases said on Monday.

The substance faces a lot more testing but investors seized on media reports of it on Monday, pushing the shares of a chemical firm involved in the project, NOF Corp <4403.T>, up nearly 21 percent.

Traditional flu vaccines create antibodies which act against flu viruses, but since virus surfaces frequently mutate, different vaccines have to be made every year.

The group found that when a peptide derived from the influenza virus is induced into mice, it could act against cells infected by multiple strains of influenza, including bird flu.

Part of the research was reported in the Journal of Immunology in 2006, and the group presented its findings last month at Japan's National Cancer Center. The only tests so far have been on mice.

The next step is to develop a vaccine that works against multiple strains of flu and is proved safe for humans, said Tetsuya Uchida, a senior investigator at the National Institute of Infectious Diseases.

"It usually takes about five years to develop vaccines for clinical use. But bird flu is an emerging issue and we would like to develop this as soon as possible," Uchida said.

The findings could also potentially be applied to create drugs to treat AIDS, tumours and other diseases, he said. (Reporting by Yoko Kubota; Editing by Sanjeev Miglani)

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