Discolored Adimmune flu vaccine dose found in Keelung: CDC

Taipei, Oct. 12 (CNA) The Centers for Disease Control (CDC) said Saturday that a discolored dose of the Adimmune influenza vaccine was found in Keelung that day, from a batch of 183,000 doses that have already been distributed to six cities and counties.

The Keelung City Health Bureau reported Saturday that one dose of flu the vaccine manufactured by Adimmune Corp. was found to have discoloration before being administered at Qidu District Public Health Center, according to a news statement issued by the CDC.

That dose of vaccine was immediately withdrawn for further investigation, the CDC added.

CDC Deputy Director-General Lo Yi-chun (羅一鈞) said that the batch containing the discolored flu vaccine dose consisted of around 183,000 doses, which had been distributed to health bureaus in six cities and counties, including Taipei, Keelung, Taoyuan, Miaoli County, Hualien County and Taitung County.

Of the total doses from the batch, 75,000 had already been administered, while the 108,000 doses remaining in stock have been temporarily withdrawn, Lo noted.

The Qidu District Public Health Center inspected over 70 doses from the same batch (FSZA2408) produced by the Taiwan-based vaccine maker, but no others were found to have discoloration, he added.

A similar situation occurred with a dose of flu vaccine manufactured by the French pharmaceutical company Sanofi six years ago, Lo said, noting that a protocol was established at the time, which includes immediately halting the administration of remaining doses from the same batch.

The Taiwan Food and Drug Administration (TFDA) has also asked Adimmune to investigate the cause of the discolored dose and determine if it is an isolated case or a systemic issue, Lo added.

At present, the incident will not affect the ongoing free influenza and COVID-19 vaccination program, which began on Oct. 1, Lo said, emphasizing that 6.254 million doses of flu vaccines from five different brands are still available for this year's program.

Regarding the possible causes of vaccine discoloration, Hwang Kao-pin (黃高彬), deputy head of the infection control center at China Medical University Hospital, said it is usually due to issues with the cold chain -- the temperature-controlled process for storing and transporting vaccines -- or improper sealing, thus leading to abnormalities.

The discoloration could be caused by incorrect temperature, a faulty cap that failed to properly seal the vaccine, or an issue with how the vaccine was stored in the public health center in Keelung, Hwang added, stressing the importance of quickly checking other batches to determine the actual cause.

A meeting is planned on Monday with medical experts and representatives from the TFDA, Keelung City Health Bureau, and Adimmune discussing vaccine quality and administration safety, according to the CDC.