After nine months of continuous efforts, the Chinese government has confirmed that a SARS vaccine has finally been developed and is entering a preliminary clinical testing period. This would be the world's first SARS inactivated vaccine approved for testing on humans. However, Chinese officials say it will still take time to make the vaccine marketable.

Actually, an inactivated vaccine is a dead virus. When injected into the human body, it does not cause disease, but produces antibodies which make the human body immune to the disease.

The first phase of testing will try to determine if it is safe and effective on the human body. Zheng Xiaoyu, director of the State Food and Drug Administration says though the SARS vaccine has passed his administration's evaluation, as with any new medicine, the clinical testing phase is only one phase of its development. There is still much to be done before the vaccine is marketable.

"It does not mean that the vaccine can be put into production right now. It is only the first phase of clinical tests. And depending on the results, we will decide whether or not to carry out the second and third phase tests."

The national SARS vaccine technical group notes the vaccine will soon be tested on 30 healthy volunteers between the ages of 20 and 50 years old. They will all be selected from areas which were not hit by the outbreak of SARS last spring.

If the vaccine proves safe and effective, more volunteers will take part in the second phase of testing, which will last longer. As for the third phase, all the volunteers will come from the epidemic-stricken areas.

However, Cao Wenzhuang, another official from the State Food and Drug Administration remains prudent.

"In accordance with international practice, when a new kind of medicine enters a clinical test, chances are high that it will be eliminated. In developed countries, between 85 and 90 percent of medicines are eliminated at this stage. So our SARS vaccine also faces the same risk."

Nevertheless, Chinese officials say whether or not the test is successful, the move is a milestone in the country's anti-SARS efforts. It will be of great significance to SARS research not only in China but also the world at large.

(CRI January 21, 2004)