Laboratories worldwide have been racing to find a cure and a vaccine for the deadly respiratory disease, which has infected over 8,200 people around the world, killing 729 of them, since it emerged in southern China in November.

Guan Yi, an assistant professor of microbiology at the University of Hong Kong, said the team will soon test the vaccine on monkeys.

"We cannot tell when the vaccine will be safe or effective in humans," he said.

He could not say how long the experiments would take.

Guan said scientists had cultured the SARS virus in their laboratories and will kill or inactivate it for the tests.

"We will then purify them to guarantee there is no live virus before testing them on animals. We will then see if the cultured virus will stimulate the production of antibodies," Guan said.

The presence of antibodies would theoretically provide some measure of immunity against SARS, which is caused by a member of the coronavirus family, which also causes the common cold.

Experts have said it would take years before any such product could be made commercially available, if at all.

If the virus is mutating rapidly, as some scientists argue, a vaccine may take much longer to develop or may not be effective at all.

Scientists at the University of Hong Kong said last week that the virus likely jumped to humans from the civet cat.

Their tests showed that viruses found in the exotic animal were very similar to the coronavirus found in SARS patients.

A World Health Organization official later warned that it was too early to jump to firm conclusions that the civet cat was the definite reservoir or host for SARS.

But authorities in some parts of southern China have since renewed a crackdown on the sale and consumption of wild game and Hong Kong has banned the import of civet cat meat.

(China Daily May 27, 2003)