The Food and Drug Administration has urged China to investigate approximately 570 million yuan ($88 million) worth of improperly refrigerated vaccine sold since 2010, which could put patients' lives at risk.
The suspects, a woman named Pang and her daughter, Sun, who graduated from medical school, have been bulk-selling 25 kinds of vaccines for adult and children through unlawful businesses since 2010.
According to police, the vaccines were purchased by 247 people in over 10 provincial regions including Chongqing as well as Shaanxi and Jilin provinces, spreading across 18 regions including Henan, Anhui and Guangdong provinces. The vaccines include flu, hepatitis B and rabies.
Pang's bank account saw some 310 million yuan of income in the past five years.
The suspects have been charged with running an illegal business and are waiting for a trial, adding that some 20 cities have been urged to cooperate with the investigation and verify the vaccine's users.
Another six suspects have been arrested in areas including Inner Mongolia, Hebei and Shandong, while another 10 have been detained.
According to local police officer Chen Bo, the temperature of the vaccine warehouse was close to 14 C when the mother and daughter were arrested and the vaccines were stored without refrigeration.
Pang, 47, once worked as a pharmacist at a hospital in Heze, Shandong and has also run a clinic selling vaccines. She is also reportedly well known for her close connections with pharmaceutical companies. In 2009, she was put on probation for illegally selling vaccines and she remains on probation.