BANGKOK - China needs more high-level international collaboration in HIV vaccine research and development, which is now somewhat hindered by government restrictions, a leading expert said.

Zhang Linqi, director of the Comprehensive AIDS Research Center at Tsinghua University made these remarks on Wednesday on the sidelines of the global conference AIDS Vaccine 2011 in Bangkok.

"The HIV vaccine development in China has been limping along despite constantly increasing government funding, and an enhanced global partnership in a comprehensive, in-depth and high-level manner would help drive that forward fast," he said, urging the government to be more open.

China is conducting four HIV vaccine studies, all fully sponsored by the government and with solely Chinese researchers participating.

However, almost all of the major achievements in the field so far - such as those seen in the RV144 trial conducted in Thailand - were based on international collaboration, Zhang said.

Some 30 years into HIV vaccine studies, RV 144, involving more than 16,000 adult volunteers, is the first and only trial to show some ability to prevent HIV infection, and was distinguished by its international collaboration involving partners from the Thai and United States governments, private sectors, and non-profit organizations.

"The collaboration is unprecedented and has proven to be a successful model for future vaccine studies worldwide," said Punnee Pitisuttithum, from the Mahidol University in Bangkok, who also took part in the trial.

Shao Yiming, chief AIDS expert for the Chinese Center for Disease Control and Prevention, however, said such international cooperation is not likely to happen in China largely because of policy constraints.

Currently, no vaccines made in foreign countries have been allowed to conduct clinical trials on the Chinese mainland, according to China's State Food and Drug Administration (SFDA).

"Procedures to get approval for a vaccine trial are complicated, usually with long delays, which has also made foreign practitioners reluctant to seek cooperation in China," Tsinghua's Zhang said.

As leader of the study of Tiantan, China's only vaccine candidate, which has finished the first phase clinical trial, Shao filed an application with the SFDA in April to proceed to phase two.

"So far, I've heard nothing from them and have no idea when we can start," he said.

In the US and Thailand, for example, such trials could get fast-track approval, buying more time for the research.

A veteran HIV vaccine researcher, Zhang said he was struck by the fact that Thailand had progressed largely thanks to international cooperation.

"China, which excels in matters like research funding, infrastructure, and human resources, should be more involved in international collaboration, particularly at the State level, to try to secure a place in the world's leading HIV vaccine studies in the future, for the benefit of mankind," he said.

Meanwhile, "besides welcoming foreign cooperation, China can go abroad, for example to Africa, the region hardest hit by HIV/AIDS, to form partnership there for vaccine development", he added.