Authorities in Anhui Province's Sixian County have detained three health workers after a mass inoculation killed a child and left 120 others hospitalized.
Investigators are now hunting for a private businessman who is alleged to be a major supplier of the suspect hepatitis A vaccines.
Meanwhile, the county government has suspended group inoculations for the disease.
Under arrest are Zhou Shimin, director of the Dazhuang Town disease prevention station; Hou Huafeng, another top station official; and Zhou Shikai, a medical worker with the station who handled the purchase of the vaccines.
The center reportedly bought 3,000 units of vaccine from businessman Zhang Peng and another 1,000 from the county's disease prevention center.
The town disease prevention center sent clinic doctors to 19 primary and middle schools in 17 villages on June 16 and 17 and injected about 2,500 students with hepatitis A vaccine, Chinese media reported.
The center didn't consult local authorities on the mass inoculation but arranged it directly with the schools, according to news reports.
During the inoculation on June 17, some primary school children began suffering dizziness, breathing difficulties and limb numbness.
By last Saturday, Sixian hospitals had admitted 121 children who had received injections.
(Shanghai Daily June 27, 2005)