About 39,000 residents in Beijing had been inoculated with A/H1N1 flu vaccine by Tuesday afternoon, with 14 cases of adverse reaction, an epidemic control expert said Wednesday.

Liang Xiaofeng, director of the immunization center under the Chinese Center for Disease Control and Prevention, said four of the 14 adverse reactions "may be" related to the vaccines.

"We are still investigating the reasons," Liang said.

Liang also said there was still uncertainty about the safety of vaccination for "sensitive groups" such as pregnant and breastfeeding women.

So far, no deaths from A/H1N1 flu have been reported on the Chinese mainland, but Taiwan has reported 17 deaths of whom two were pregnant women.

On Monday, more than 10,000 students and performers in Beijing who are to take part in the National Day parade and performances on Oct. 1 received vaccinations, with no adverse reactions, the Beijing Municipal Bureau of Health said Tuesday.

China issued a warrant for mass inoculation with A/H1N1 flu vaccine on Sept. 8 after it approved Sept. 3 vaccine produced by domestic pharmaceutical company Sinovac.

By Monday, more than 13,000 confirmed cases of A/H1N1 flu had been reported on the Chinese mainland, about 66.4 percent of whom have recovered. Among the new cases, the percentage of those infected within China had increased.

(Xinhua News Agency September 23, 2009)