During the COVID-19 outbreak, foreign substances such as mold, hair, and silicon dioxide (silica) that could have been introduced during manufacturing were found in vaccines, yet the disease control authorities did not halt vaccinations and continued administering the shots. Even after the foreign substances were reported, about 14.2 million additional doses from the same lot numbers were administered.
According to the Board of Audit and Inspection's report "Diagnosis and analysis of the COVID-19 response" released on the 23rd, the Korea Disease Control and Prevention Agency received 1,285 reports of foreign substances in COVID-19 vaccines from medical institutions between March 2021 and October 2024.
Of these, 835 cases (65%) involved rubber stopper fragments that fell in during administration. Reports of foreign substances of concern, such as mold, hair, and silicon dioxide, totaled 127 cases (9.9%).
Under the government manual, when foreign substances are found in a vaccine, the disease control agency must request a quality review from the Ministery of Food and Drug Safety, and the agency must notify the results after component analysis and other reviews. If necessary, vaccination with the affected lot numbers must be put on hold, or the products must be collected and tested.
However, according to the Board of Audit and Inspection, the disease control agency did not notify the Ministery of Food and Drug Safety of the reports and informed only the manufacturer. It closed the cases by accepting the manufacturer's internal investigation results without separate verification. In the meantime, about 14.2 million additional doses from lot numbers for which foreign substances of concern had been reported were administered.
Cases of administering expired vaccines also came to light. The Board of Audit and Inspection said that between 2021 and 2023, 2,703 people received COVID-19 vaccines past their expiration dates.
The disease control agency did not specify in the COVID-19 vaccination standards that recipients must be informed when expired vaccines are administered, and it did not separately track whether they were revaccinated. As a result, 1,504 of the 2,703 people (55.6%) did not receive revaccination.
Even so, the disease control agency issued vaccination certificates to them.
The Board of Audit and Inspection also pointed to structural confusion in the quarantine system under the Moon Jae-in administration. Although the Central Disease Control Headquarters of the disease control agency, the Central Disaster Management Headquarters of the health ministry, the pan-government Central Disaster and Safety Countermeasures Headquarters, and local governments operated simultaneously, laws and manuals did not clearly delineate roles and responsibilities by institution, leading to delays and confusion.
In fact, the health ministry and the disease control agency delivered conflicting messages without prior coordination. When the health ministry said, "Election campaigning is not subject to the ban on gatherings of five or more," the disease control agency said it was "subject to the rule," and they also gave conflicting explanations on the effectiveness of cotton masks and whether there would be vaccine incentives.
There were also mismatches between central and local governments. While the central government took a cautious stance on introducing at-home test kits, the Seoul city government announced plans to introduce them, and some local governments lifted the indoor mask mandate on their own judgment, contrary to the central policy of easing it in stages.
Confusion also arose in the process of elevating the Korea Centers for Disease Control and Prevention to the disease control agency. The Board of Audit and Inspection said that as the reorganization proceeded in 2020 without clearly defining the lead body for vaccine introduction negotiations, the health ministry and the disease control agency each viewed it as the other's responsibility, delaying the talks by more than a month.
There were gaps in epidemiological investigations as well. When confirmed cases occurred on flights, passengers in adjacent seats were quarantined, but crew members in that section were not classified as contacts, leaving at least 658 and up to 9,514 people out of quarantine. Many cases of missed quarantine were also confirmed because there was no system to share contact information across regions, forcing reliance on email and official letters.
In response, the disease control agency held a briefing that day and said it would "actively accept" the audit findings. However, regarding vaccines with foreign substances, it explained, "When foreign substances were reported during administration, the vaccines were isolated and stored, and there were no cases of actual administration."
It also emphasized, "Manufacturer investigations found no manufacturing or process-related quality issues in the 14.2 million doses from the same lot numbers."
The disease control agency added, "During the pandemic, we often requested investigations directly from manufacturers without going through the Ministery of Food and Drug Safety, and we did not suspend vaccination of entire lot numbers while awaiting investigation results."
It also said it would spell out procedures for reporting and requesting quality investigations when vaccine quality issues are found, and it would supplement guidelines and systems for managing misadministration. The Ministery of Food and Drug Safety also said it would introduce a quality verification system for vaccines under emergency use authorization and establish a legal basis.
The Board of Audit and Inspection notified a total of 31 improvement measures to four agencies: the Ministry of Health and Welfare, the Korea Disease Control and Prevention Agency, the Ministery of Food and Drug Safety, and the Ministry of the Interior and Safety.
However, citing that in March 2020, then-Board of Audit and Inspection chief Choe Jae-hyeong said, "We will not hold people accountable in the absence of personal corruption in the process of responding to a national crisis," no personnel actions such as disciplinary measures were taken against those involved.