SARS Fears Growing in U.S.
4 in 10 Americans Worried About SARS
Is the SARS Virus Mutating? continued...
Osterhaus was the leader of the research team that provided the conclusive evidence based on animal testing that a previously unknown coronavirus was indeed the cause of SARS. He says it's still too soon to say what might causing subtle genetic differences found in the newly discovered SARS virus in samples from different SARS patients.
"It is still hard to say what the mutations mean," Osterhaus tells WebMD. "Whether these mutations represent escape variants or differences in individual patients' immune response to the virus, we don't yet know."
CDC Director Julie Gerberding, MD, says although researchers moved with unprecedented speed in isolating and sequencing the SARS virus, there is still much more work to be done.
"I'd love to know why some patients are sicker than others, and why in some populations there seems to be a higher attack rate of the pneumonia in others, but it's just really preliminary I think to ascribe that to the virus, per se. We have a lot to learn," says Gerberding.