Approximately 14.2 million doses of COVID-19 vaccines from the same lot numbers as those reported for contamination with mold and other foreign substances were administered, according to an audit. An additional 2,703 people received expired vaccines.
The Board of Audit and Inspection released its "COVID-19 Response Assessment and Analysis" on Wednesday, revealing that 1,285 reports of foreign substances in vaccines were filed by medical institutions between 2021 and 2024. Despite discoveries of contaminants in specific lots, vaccinations using the same lot numbers were not immediately suspended, resulting in approximately 14.2 million doses being administered after contamination reports.
Among reported contaminants, 835 cases involved rubber stopper fragments and other materials that may have occurred during handling. However, 127 cases (9.9%) involved potentially hazardous substances including mold, hair, and silicon dioxide.
The audit board noted that vaccinations continued in many cases before investigation results were available. The adverse reaction reporting rate for the affected lot numbers was up to 0.265 percentage points higher than the average for other lots, though the board said it is difficult to establish a causal relationship between contaminants and side effects at this time.
A Korea Disease Control and Prevention Agency (KDCA) official said, "Investigations by vaccine manufacturers found no manufacturing or processing problems in vaccines with the same lot numbers."
The audit also found that 2,703 people received expired vaccines between 2021 and 2023, with some even issued vaccination certificates. Additionally, 1.31 million doses were used without undergoing national lot release testing to verify quality by lot number. The audit board pointed to confusion and delays caused by unclear roles and responsibilities among agencies.
The KDCA said it accepts the audit findings and will incorporate them into its "Infectious Disease Crisis Management System Enhancement Plan." The agency plans to introduce a quality verification system for emergency-use authorized vaccines in May and establish protocols requiring confirmation of national lot release approval before administration. Procedures for reporting quality issues to the Ministry of Food and Drug Safety and requesting quality investigations will also be formalized.
The agency will also improve its integrated quarantine information system to strengthen epidemiological investigation data sharing between public health centers. A "Public Health and Social Response Manual" with detailed social distancing and cohort isolation standards will be established in the first half of the year.
"We will use this audit as an opportunity to reorganize our crisis communication and cooperation systems and respond more systematically to future novel infectious disease outbreaks," a KDCA official said.