Doctor Anthony Fauci, who heads the National Institute of Allergy and Infectious Diseases, told Congress Monday there was a mounting body of evidence that Severe Acute Respiratory Syndrome (SARS) is caused by a novel coronavirus that may have crossed species from an animals to humans.

Coronaviruses, which have been known to US scientists for years, are usually not seen as a major public health hazard because they cause no more than the common cold.

But Fauci said the coronavirus believed to be associated with SARS is a previously unidentified type. Moreover, there was some evidence that in its attacks on humans, the coronavirus was aided by a second yet to be identified pathogen.

"Fortuitously, vaccines against common veterinary coronaviruses are routinely used to prevent serious diseases in young animals, such as a vaccine given to pigs to prevent serious enteric coronavirus disease," Fauci told the Senate Committee on Health, Education, Labor and Pensions.

"These models could prove useful as we develop vaccines to protect humans," the researcher added.

The word of optimism came as the mysterious epidemic continued to spread across Asia and the rest of the world, curbing international travel and business contacts.

Fauci said work on an anti-SARS vaccine was already under way at his institute.

"We now have that virus growing," he said in a later interview with PBS Television. "Once have you it growing in a laboratory, then you can do things with it that can speed the process enormously, with regard to vaccine, therapeutics and diagnostics."

But he cautioned that researchers still had "a long way to go" in creating a viable vaccine because they had much to learn about the disease.

Fauci said he had seen no evidence the virus had been created as a biological weapon in laboratory conditions, but refused to entirely dismiss that theory pending further study.

"Until then, we will keep our minds open to these possibilities, however remote," he pointed out.

(People?s Daily April 9, 2003)