The breakthrough is based on "chemical genetics," or the use of chemicals to thwart viruses from replicating.

Using the method, developed jointly by the University of Hong Kong and the Aaron Diamond AIDS Research Center, new emerging viruses are screened against a chemical library of more than 50,000 molecule compounds.

The scientists recently tried out the new approach, called the high-throughput screening platform, on the SARS virus and found that 104 of the chemicals could arrest the bug.

Richard Kao, research assistant professor of microbiology at the University of Hong Kong, said the screening process may be applied to any new, emerging virus.

"When there is a new virus, we can jump onto this high-throughput screening platform and screen more than 50,000 molecules and see which one of them can stop the virus from killing cells," Kao told a news conference.

"We expect around 100 of these molecules to be able to inhibit any new virus. We will then take these 100-plus molecules and see if any of them are suitable for testing in animals."

If these could effectively inhibit the virus in animals and were not toxic the molecules could be tried in clinical trials on humans, Kao said.

However, it was too early to say if a SARS drug could be developed with the new method.

The University of Hong Kong was the first institution to identify the SARS virus last year, narrowing down its source to a number of wild animals including the civet cat, which is eaten in southern China.

Nearly 300 people in Hong Kong were killed by the SARS virus. It surfaced in southern China and was brought into tiny, congested Hong Kong by travelers. It has never been established how the virus jumped the species barrier from animal to human.