Scientists in search of a SARS cure have narrowed their focus to several dozen drugs that appear to have the best chance of stopping the deadly respiratory virus, but they have abandoned plans to test one of them in people.

The urgent hunt for something that works — preferably a medicine already on the market or close to it — was helped by the breakthrough a week ago in decoding the virus’ genetic makeup, which gives scientists some logical targets.

The drug ribavirin is being used in Hong Kong and Toronto by doctors who are convinced it helps many SARS patients. But U.S. researchers, who have been skeptical all along, shelved a plan to formally test the drug with a careful experiment in people.

The decision was made this week after testing at the U.S. Army Medical Research Institute for Infectious Diseases at Fort Detrick, Md., found no evidence that the drug has any effect against SARS virus growing in tissue cultures.

Lab testing is under way or will begin this week on all the other antiviral drugs on the market. These are 16 AIDS drugs, 13 herpes drugs and seven aimed at flu and other viruses.

Also to be tested are seven forms of interferon, which are the body’s natural microbe killers.