China's quality watchdog Friday recalled a human rabies vaccine produced in 2008 by a Liaoning province company which contained an illegal nucleic acid ingredient.

The ingredient acts as an adjuvant, a substance used to enhance the effectiveness of a drug or a pesticide.

The rabies vaccine, produced by Dalian Gold Hong Kong Company, failed the test launched in January by National Institute for the Control of Pharmaceutical and Biological Products .

Yan Jiangying, a spokeswoman from General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) said the nucleic acid materials could not be used as an adjuvant for the rabies human vaccine, since "the experiment had not entered human clinical trials yet."

"Although its effect on animals turned out safe, any usage of this ingredient is illegal before we finish trials on humans," Yan said.

She also revealed people who had taken the vaccination were under close attention by the watchdog and no adverse reaction cases had been reported yet.

(Xinhua News Agency February 7, 2009)