Drug hope for Sars

The Coronavirus is thought to cause Sars

Drugs already in existence could - with slight modifications - be used to combat the coronavirus thought to be responsible for Sars, say scientists.

Experts have reached this conclusion after working out the structure of a substance made by the coronavirus called main proteinase.

This enzyme is vital to the survival of the virus, because it enables it to reproduce.

Scientists believe it should be possible to use drugs to lock on to it and stop it from working.

In fact, they believe that some drugs already in existence should do the trick.

However, they would need to be modified to make them effective.

Lead researcher Dr Rolf Hilgenfeld, from the University of Lubeck, believes progress towards an effective treatment will be rapid.

He said: "I think it could be very fast now because we have a very detailed template now for the design of new drugs.

"To turn these into real drugs, including clinical trials and so on, will of course take much longer, probably a couple of years."

Cold virus

The drugs which Professor Hilgenfeld has been working with have been developed to fight cold viruses, and are already in clinical trials.

This suggests that if they were modified to fight coronavirus, they would still probably be safe, though the full regime of clinical trials would still be needed.

The World Health Organization (WHO) remains optimistic that isolation and quarantine measures will be enough to stop the spread of Sars.

But the latest epidemic figures from mainland China and Taiwan suggest that their strategy may not be working - in which case effective drugs will be a high priority.

The researchers did not actually examine the main proteinase of the coronavirus responsible for Sars.

Instead, their work focused on the structure of the main proteinase produced by two other coronaviruses, one that infects humans and one that infects pigs.

They then applied gene analysis techniques to show that the Sars coronavirus produces main proteinase with virtually the same structure.

The research is published on the website of the journal Science.