In three-phase clinical trials of China's first joint HIV/AIDS vaccine the first stage has been completed in Nanning, capital of south China's Guangxi Zhuang Autonomous Region.

The 15-month-long trial came to an end over the weekend as scientists of the Guangxi Regional Center for Disease Control and Prevention completed follow-up examinations on 49 volunteers treated with the vaccine.

Researchers will author a report based on statistics and experimental data collected during the trials. The State Food and Drug Administration will examine the report and decide whether the center can go ahead with phase two.

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

Currently all data shows that the reactions of the vaccine users are normal and researchers are confident about approval for the second phase to be progressed, Chen noted.

The second phase of the trials would assess antibody induction and continue to look at the safety of the vaccine, Chen added. More volunteers would be recruited. The third phase will focus on testing the vaccine's ability to protect high-risk groups including drug users and sex workers.

A vaccine can only be approved for production and use after it passes the three phases.

Currently around the world 35 AIDS vaccines are being tested on humans with the majority of them 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 to be a failure.

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

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

"A special national foundation should be established to enhance the development of a vaccine and 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 had been slow, Zeng said. In developed countries thanks to good public education, medical treatment and high-risk activities intervention the epidemic has been effectively controlled, he explained.  

However, for developing countries like China, more action required to be taken in AIDS education, prevention and control, Zeng said. Because of this a vaccine was urgently needed to curb the rapid spread of the virus.

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

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

(China Daily June 12, 2006)