Vaccine could take years to develop
By Richard Spencer and Roger Highfield, Science Editor
Vaccines or drugs to fight Sars could take years to reach patients, while there are concerns that the virus responsible for the disease could evolve
to become more deadly, scientists said yesterday.
Because of the long lead time involved in bringing a new treatment from the lab to the surgery, Sars drugs could take years to emerge, according to Dr
Anne Bridgen, of the University of Ulster.
The disease agent, a coronavirus, is one of those responsible for the common cold and is also common in animals, she said. "There is as yet no drug
treatment that can either prevent or cure a coronavirus infection."
Leo Poon, associate professor of the University of Hong Kong school of medicine, said the virus was based on a RNA genetic sequence which was prone to
mutate. This raises the possibility of it reappearing after a "lie low" period in a more virulent form.
While the teams studying the virus are agreed that the future course of the disease cannot be predicted with any certainty, many are describing the
coming months as a "window of opportunity" to eradicate it before it becomes endemic.
Reported new cases in Guangdong, the southern Chinese province where the disease is believed to have originated five months ago are starting to fall,
the World Health Organisation said yesterday.
The death rate from Sars is five to six per cent compared with 30 per cent for smallpox
Most deaths are in older people and in those with other diseases.
Latest WHO figures are 4,288 cases and 251 deaths
Cases rose by 343 over the last two days
Classic symptoms for Sars are a rapid rise in temperature, a dry cough and shortness of breath
The incubation period is about 10 days
Doctors say Sars is infectious only when symptoms have occurred
People are advised against travelling to China, Toronto and Hong Kong