Regulators track down 9 firms in vaccine scandal

China's Food and Drug Administration has tracked down nine pharmaceutical companies implicated in the vaccine scandal.

They were found to have fabricated distribution channels and will be primarily held responsible for the illegal circulation of problematic vaccines, the administration said.

Three of the companies are based in Shandong Province, two in Shaanxi Province and the rest in Hebei, Henan, Hunan, and Jilin provinces.

They include Hebei Weifang Biological Production Supply Center, affiliated to Hebei Disease Control and Prevention Center, and Shandong Shijie Biological Pharmaceutical Co Ltd, listed on the "New Third Board," or National Equities Exchange and Quotations.

Investigators in the six provinces have been urged to check possible violations and report their findings by March 25.

Investigators in Changsha, capital of Hunan, have been sent to the Hunan Huayi Biological Production Co Ltd, one of the nine blacklisted firms. Xinhua News Agency reported that one arrest has been made in the scandal.