Japan Suspends 1.6 Million Doses of Moderna Vaccine After Reports of Contamination

No reported safety incidents so far

A Moderna COVID-19 vaccine vial in an undated file photo. (Eugene Hoshiko/AP Photo)

Japan announced on Aug. 26 that it's suspending the use of about 1.63 million doses of the Moderna COVID-19 vaccine due to reports of contamination.

The country’s health ministry said “foreign materials” were found in at least 390 doses—or 39 vials—of the Moderna vaccine coming from eight vaccination sites, according to The Asahi Shimbun.

Takeda Pharmaceutical, a Japanese drugmaker distributing the Moderna vaccines in Japan, had received reports of contamination from multiple vaccination sites. The health ministry subsequently learned of the matter on Aug. 25, the outlet reported.

"It's a substance that reacts to magnets ... it could be metal," a ministry official reportedly said, according to Nikkei Asia.

The reports of contamination involve a batch that has a total of 565,400 doses. The ministry said it decided to suspend the lot as a precaution after it had consulted with Takeda. It also suspended another two batches.

The three batches altogether contain 1.63 million vaccine doses, which have been distributed to 863 vaccination centers across the country. The ministry will request that the centers not use them.

Officials said that an unknown number of doses from the affected lot have been administered, but there have been no reported adverse effects thus far.

Takeda said in a statement that it had asked Moderna to investigate the safety of the vaccine as a matter of emergency. It also shared the batch numbers, which are 3004667, 3004734, and 3004956.

"Moderna confirms having been notified of cases of particulate matter being seen in drug product vials of its COVID-19 vaccine," Moderna said in a statement. "The company is investigating the reports and remains committed to working expeditiously with its partner, Takeda, and regulators to address this.”

The health ministry said that all of the vaccines currently being rolled out in Japan are manufactured by a company based in Spain.

It wasn't immediately clear whether the issue affected supplies of the Moderna vaccine to other countries.

Chief Cabinet Secretary Katsunobu Kato said that the Japanese government is discussing ways to minimize the effect on the country’s vaccination rollout with Takeda.

“We will do [our] utmost in order to avoid any impact on vaccination progress, especially at worksites and large-scale centers,” Kato said.

About 43 percent of the population in Japan has been fully vaccinated; about 50 percent have received at least one dose.

The Associated Press and Reuters contributed to this report.