Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Biotech / Medical : SARS and Avian Flu -- Ignore unavailable to you. Want to Upgrade?

To: maceng2 who wrote (1233)	1/20/2004 4:30:18 AM
From: Doc Bones	Read Replies (4) \| Respond to of 4232

China Approves Human Trials Of Experimental SARS Vaccine By MATT POTTINGER Staff Reporter of THE WALL STREET JOURNAL HONG KONG -- China gave permission for doctors to start injecting an experimental SARS vaccine into volunteers, in the first such step anywhere and one that experts said carries risks. The so-called first-phase vaccine trial, announced by state media Monday, would test the safety of the vaccine in humans. "The vaccine was found safe in experiments on animals, including the rhesus monkey," Zheng Youyu, director of the State Food and Drug Administration, was quoted as saying by the Xinhua news agency. Some 30 people have volunteered for the trial, state television reported. Mr. Zheng was quoted as saying it would be some time before a vaccine would be ready for widespread use. The development of a safe and effective vaccine would mark a significant step in efforts to prevent outbreaks of severe acute respiratory syndrome, which last year spread to 30 countries from southern China before the epidemic petered out. It killed 774 people world-wide and sickened more than 8,000. In China, 349 people died. China says the disease resurfaced recently in three people in the southern city of Guangzhou, though they don't appear to have spread SARS. Developing a vaccine is a matter of national pride for China. Scientists from Hong Kong and abroad have made most of the significant discoveries about SARS, and scientists in other countries also are working on vaccines. Monday's announcement "indicated that China had taken the lead in this field," Xinhua said. But testing a new vaccine carries special risks. The Chinese media reports suggested the experimental vaccine is of a type known as "killed-virus" vaccines. It would entail cultivating large quantities of the live SARS virus, inactivating the virus with chemicals or with heat, and then injecting it into the body. Because the virus is dead, it can't give people SARS, but it is hoped it will prompt an immune response that can defend people in case they are exposed to the real thing. "The first risk would be, 'Is it properly killed?' " said Wolfgang Preiser, a doctor at the Institute for Medical Virology at J.W. Goethe University Hospital in Frankfurt. Modern technology makes it fairly easy to ascertain the virus has been killed properly, he said. The second risk is that the animal cell-cultures used to grow the live virus may carry infectious pathogens that could be passed accidentally to people as part of the vaccine. The third risk, Dr. Preiser said, is perhaps the greatest. With some diseases, vaccines actually can have the opposite of their intended effect: They prime the immune system to overreact, rather than to protect, the body. In such cases, vaccinated people are worse off than unvaccinated people when they are exposed to a live virus. Dengue fever is one such disease. People who suffer a mild infection with one strain of dengue are at greater risk of developing hemorrhagic fever if later they are infected by another strain. The SARS virus, which causes a hyperimmune reaction in many patients, might be a similar kind of disease. "I don't think we can rule out that," Dr. Preiser said. Write to Matt Pottinger at matt.pottinger@wsj.com Updated January 19, 2004 7:11 p.m. online.wsj.com