Experts confirmed yesterday that second phase human trials of a SARS (severe acute respiratory syndrome) vaccine will go ahead, involving 300 volunteers aged 20 to 60.

Scientists in Beijing will test the effectiveness of the inactivated SARS vaccine in people, Zhong Nanshan, president of Chinese Medical Association, told Guangzhou-based Nanfang Metropolis.

According to Yin Hongzhang from the State Drug Administration (SDA), the first phase involved 36 volunteers at the Sino-Japanese Friendship Hospital in Beijing from May 22, 2004. By early December, antibodies were found in all of them without any obvious side effects.

The SDA is in charge of supervising trials of any new vaccine or drug.

The vaccine was produced by Sinovac Biotech Co Ltd, based in the capital, last year after outbreaks of SARS in 2003 and 2004 killed at least 350 people, mostly in China.

Zhong did not say when the second phase would start or which hospitals would take part.

The volunteers will undergo medical examinations to record the persistence of antibodies over a nine-month period after the vaccine is administered, Zhong said.

The first phase was designed to show the vaccine could build antibodies in humans without side effects, but not to see how long they remain, Zhong added.

Only after a vaccine has passed three phases of human trials will it be licensed for public use.

Up to now, no volunteers who took part in the first phase have reported any side effects, said Zhong.

"I am fine and have been healthy since I got the vaccine on May 22, 2004," Lan Wanli, a university student based in Beijing, said yesterday. He was the first person in the world to receive the vaccine.

The second phase will involve further verification of issues such as dosage and timing of injections to gain a better understanding of how the vaccine could be used most effectively, experts said.

(China Daily July 7, 2005)