The second phase of a human trial for China’s potential HIV vaccine started on Tuesday in Beijing.

About 150 volunteers, mostly those with a high risk of contracting HIV, including gay people, took part in the clinical trial.

Shao Yiming, director of the virology and immunology department of the National Center for AIDS/STD Control and Prevention, said at a news conference that the trial will last nearly two years in the Beijing You’an Hospital of the Capital Medical University.

"The phase 2 clinical trial mainly aims to test the vaccine’s safety and is crucial for the introduction of the next phase, which will test its effectiveness," Shao told China Daily.

"The vaccine candidate is promising, as the phase 1 trial conducted among 46 volunteers found that it could induce immune responses to HIV among some recipients," said Shao, one of the founders of the China AIDS Vaccine Initiative.

Results of the latest trials are expected to be released in two years, said Zhang Chong, a doctor with Beijing You’an Hospital.

"We’ll also provide follow-up services, including testing and medical examinations, after the volunteers receive the vaccination four times," she said.

Fifteen people got the first vaccination on Tuesday.

Li Yewen, a 28-year-old salesman in Beijing, was one of them. He is gay.

"I feel well after the vaccination, and there are still three more," he told China Daily over the phone.

Doctors informed him beforehand of potential adverse reactions like itching and redness where he got the injection, he said.

"As one of the vulnerable group to HIV/AIDS, I’d like to take part in the clinical trial and help with the research and development of a successful vaccine that can indeed prevent people from getting HIV," he said.

According to Shao, volunteers will be regularly provided with education about healthy lifestyles, including protected sex activities, after the vaccination.

"Given that AIDS can’t be cured at the moment, a vaccine might be the best weapon to eliminate the disease that killed 1.7 million people worldwide last year," he said.

By 2011, China had 780,000 people living with HIV/AIDS on the mainland, government estimates showed.

Shao also urged the government to keep investing in the research of an HIV vaccine.

A UNAIDS report said that China invested at least $18 million in HIV vaccine research and development in 2010, making it the third-largest spender in the world after the United States and the European Union.

China currently has three major HIV vaccine candidates under development on the mainland, all financed by the government, Shao said.

"China still needs more, as many developed countries like the US usually have more than 10 to have a better chance of success," he said.