Hope for SARS Vaccine as WHO Extends China Travel WarningBy Lawrence K. Altman
and Denise Grady
New York Times -- The first major study of the genome of the SARS virus shows that it has not mutated significantly in its spread to different countries.
The findings were encouraging because if the virus remains stable chances are increased that a vaccine might be developed, the authors and other experts said on Thursday. That effort is expected to take years.
But the experts said that the findings also mean that SARS, unlike some other new and emerging diseases, has not weakened as it passed through successive generations. Some experts had expressed hope that the virus would cause less severe illness as it spread.
At the same time, the World Health Organization announced Thursday that, because of continuing spread, it was extending its warning against nonessential travel to Tianjin municipality and Inner Mongolia in China, and to Taipei in Taiwan.
Also, in a report on the outbreak in Singapore, the U.S. Centers for Disease Control and Prevention said that five individuals had acted as “super spreaders” in passing the virus to 144 other people, while 81 percent of infected people did not transmit to anyone else. CDC defined super spreaders as individuals who transmitted SARS to 10 or more other people. Doctors have described super spreaders in other infections like tuberculosis, rubella and Ebola.
CDC’s director, Dr. Julie L. Gerberding, said her agency is making available to state health departments the biological material that is needed to perform a diagnostic blood test. The test detects the antibodies that the immune system forms as it fights off infections; the immune system produces a specific antibody against each microbe.
CDC researchers have developed a test. The SARS test is expected to have limited use because it cannot detect antibodies until three weeks after the onset of illness. A positive result would strongly indicate that an individual has been infected with the SARS virus, but a negative test will not necessarily rule out such infection, Gerberding said.