Researchers confronting virus that's mutating

By Margaret Wong
Associated Press

HONG KONG — The SARS virus is mutating rapidly, developing at least two forms, which could complicate efforts to develop a solid diagnosis and a vaccine, researchers said yesterday.

"This rapid evolution is like that of a murderer who is trying to change his fingerprints or even his appearance to try to escape detection," said Dr. Dennis Lo, a chemical pathologist at the Chinese University of Hong Kong.

Researchers at the university said they have determined the genetic sequences of virus samples taken from 11 SARS patients, and that by late March there were two forms of the virus present in Hong Kong.

"We have shown that the SARS coronavirus is undergoing rapid evolution in our population," Lo said. A U.S. coronavirus expert, David Brian, at the University of Tennessee, agreed that a rapidly mutating SARS virus could complicate work toward a vaccine and reliable diagnostic tests.

The crucial question is where the mutations occur in the SARS virus genome, he said.

If they affect the shape of an outer protein on the virus, it could hamper vaccines, which rely on training the immune system to recognize particular protein shapes, he said.