The first stage of a three-phase clinical test for China's first joint HIV/AIDS vaccine has been completed in Nanning, capital of South China's Guangxi Zhuang Autonomous Region.

A woman volunteer gets a dose of HIV/AIDS vaccine in Nanning, Guangxi Zhuang Autonomous Region on March 12, 2005. [Xinhua]

The 15-month-long test came to an end over the weekend as scientists of the Guangxi regional Centre for Disease Control and Prevention finished follow-up examinations on 49 volunteers inoculated with the vaccine.

Researchers will write a report based on statistics and experimental data collected in the test. The State Food and Drug Administration will examine the report and decide whether the centre can go ahead with the second phase.

"The aim of the first-phase test is primarily to check the safety of the vaccine," Chen Jie, deputy director of the centre, was quoted by Xinhua News Agency as saying.

Currently, all data shows that the reactions of vaccine carriers are normal, and researchers are confident about the approval of the second phase, Chen noted.

The second phase of the trials will test antibody induction and continue to test the safety of the vaccine, Chen added, and more volunteers will be recruited.

The third phase will focus on testing the vaccine's ability to protect high-risk groups including drug abusers and sex workers.

A vaccine can be approved for production and usage only after it passes three test phases.

At present, about 35 AIDS vaccine are being tested on humans in the world. But the majority of them are still in the first phase.

In the 25-year history of the AIDS pandemic, at least 120 vaccines have been tested, and only one, AIDSVAX, has completed the full three-phase trial process. However, it ultimately proved a failure.

"The HIV virus has many sub-types and keeps changing. This makes it incredibly difficult for scientist to find an effective vaccine," said Zeng Yi, an expert with the Chinese Academy of Sciences.

He urged the government to invest more in research work given the country currently has over 650,000 HIV carriers.

"A special national foundation should be established to enhance the development of a vaccine. In the coming years, at least 1 billion yuan (US$120 million) must be invested," Zeng said in a report published recently.

Due to the lack of financial support and shortage of qualified researchers progress has been slow, Zeng said.

He said that in developed countries, thanks to good public education, medical treatment and high-risk activities intervention, the epidemic has been effectively controlled.

However, for developing countries like China, more action still needs to be taken in AIDS education, prevention and control.

Because of this, a vaccine is urgently needed to curb the rapid spread of the virus.

Zeng noted that the economic losses brought by AIDS to China in the coming five years are estimated to exceed 300 billion yuan (US$42.25 billion)

Among China's HIV/AIDS cases, 49.8 per cent were transmitted by unsafe sex, 48.6 per cent by drug injection, and 1.6 per cent from mothers to babies, Zeng said.

Editor: Yan