A team of scientists in Hong Kong has discovered a new class of compounds can effectively stop the deadly SARS virus from replicating and is now testing them against other viruses.

Success with other viruses will increase the scientists chances of attracting funding for further tests, animal and clinical trials, and hopefully for eventual commercial production.

The SARS virus spread across 30 countries in 2003, infecting nearly 8,500 people and killing more than 800. It re-appeared in southern China last year but there were only a few isolated cases.

Doctors tried different cocktails of drugs to cure victims at the time but no formula was very effective. Many survivors are still suffering side effects from the drugs today.

Julian Tanner, a research assistant professor of biochemistry at the University of Hong Kong, said the team first singled out a component in the SARS virus, called the helicase, which is essential for the virus to replicate.

“We did find that a class of compounds called bananins were effective inhibitors. Besides inhibiting the helicase itself, they were also effective at blocking the replication of the virus and the cell culture,” Tanner said in an interview.

The bananins were developed in recent years by Andreas Kesel, a collaborator of the Hong Kong university team. Kesel, who works in Germany, developed the compounds not specifically for SARS, but in the hunt for a general antiviral drug.

Tanner described the bananins as being “a bit similar” to the antiviral drug amantadine.

Amantadine was found to be effective in treating some patients of the H5N1 bird flu virus in Hong Kong in 1997. But doctors here say the avian virus has since mutated so much that amantadine was no longer effective by 2004.

Tanner cautioned against holding too much hope that the bananins would be commercially available to fight a re-emergence of the SARS virus anytime soon.

“It will take years, we still got to go through animal trials, clinical trials. And that won’t happen if we find that these drugs are only effective against SARS,” he said, adding that it was much easier to obtain funding for work into multi-purpose drugs.

“Unless they are effective against other viruses, then they probably won’t go through clinical trials,” he added.

“But they have a lot of potential for other major viral diseases which we are testing - hepatitis C, herpes, possibly avian flu,” Tanner said.

The team in Hong Kong is hoping to begin using the new compounds against SARS in animal trials in a few months’ time.