Authorities on Friday released the findings of a probe into a previous investigation of substandard DPT vaccines produced by Wuhan Institute of Biological Products Co.

The inspection team, formed by members of departments including the State Drug Administration and National Health Commission, found misconduct in vaccine production, as well as in fulfillment of local supervisory responsibilities.

DPT refers to a combination of vaccines for three infectious diseases: diphtheria, whooping cough and tetanus.

In the previous investigation of the incident in 2017, the punishment was too light and not in line with laws and regulations, said inspectors on the new team.

"The SDA and related government agencies will demand the rectification of the wrongdoings, hold the company and supervisory departments involved accountable, conduct re-vaccination for children affected, and release results to the public in a timely manner," the inspectors said.

The inspectors have conducted spot-checks, looked through files and documents, and interviewed relevant people since they arrived in Hubei on Aug. 1.

The batch of DPT vaccines, produced on July 19, 2016, proved substandard due to a short-term equipment failure, which resulted in improper distribution of the active constituent.

The official findings showed the company failed to take into account the malfunction and make targeted tests on the quality of its products during internal inspections. The defective vaccines were not chosen in the random test of the National Institutes for Food and Drug Control before being permitted to enter the market.

The National Institutes for Food and Drug Control found in later tests last year that the effectiveness of the vaccine against whooping cough did not meet national standards.

In Hebei and Chongqing, where the defective vaccines were sold, 71 percent and 75 percent of the children affected were reinoculated with quality vaccine against whooping cough.

All unused defective DPT vaccines have been recalled and destroyed.

Xinhua