Japan temporarily halted the use of 1.63 million Moderna vaccine doses over claims that tiny particles were found floating in unused vials

• Japan's health ministry temporarily suspended the use of 1.63 million Moderna vaccine doses.
• It said foreign substances were found in 39 vaccine vials at eight vaccination sites across five prefectures.
• The doses were distributed to 863 vaccination centers, but the facilities have been instructed not to use them.

Japan halted the use of 1.63 million Moderna doses in its vaccination drive after its health ministry reported foreign substances in some unopened vaccine vials.

Medical workers across the country reported 39 instances of foreign substances floating in unused vaccine vials, per Kyodo News. The vials were found in eight vaccination sites across five prefectures - Ibaraki, Saitama, Tokyo, Gifu, and Aichi.

The Japanese health authorities say the 1.63 million doses of Moderna vaccine are from three vaccine batches produced in Spain under the lot numbers 3004667, 3004734, and 3004956, per the Japan Times. The use of vaccines from these batches has been suspended temporarily as a safety precaution.

The substances found in the vaccine vials were tiny particles several millimeters in size, though it is unknown what exactly these particles were made of.

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

Moderna did not immediately respond to a request for comment from Insider on what the foreign substances found in the vaccines were.

Japan is employing three vaccines as part of its nationwide vaccination rollout - the Moderna, Pfizer-BioNTech, and Oxford-AstraZeneca COVID-19 vaccines. Japan has vaccinated 48.4% of its 126 million residents as of August 24. The Moderna vaccine was approved for use in Japan on May 21.

The inoculation process has, however, been relatively sluggish. In May, the Japanese government saw tens of millions of COVID vaccines go to waste because municipal governments were unable to set up supply lines swiftly to cope with the rollout, reported Japan Times. And in February, the Japanese government was forced to discard millions of Pfizer vaccines after the country's health authorities realized they did not have the right syringes to use with the vaccine vials, per the Guardian.

Several snafus have also been reported in Japan's vaccination drive. In May, the COVID vaccine booking system used for the Japanese public allowed people to make reservations using completely false information.

Japan this week hit a record number of COVID-19 infections, per Reuters. The country is reporting an average of 23,016 infections per day.

Prime Minister Yoshihide Suga also announced on August 25 that the government would expand the state of emergency from 13 prefectures to 21. On Friday, a state of emergency will be imposed on the Hokkaido, Miyagi, Gifu, Aichi, Mie, Shiga, Okayama, and Hiroshima prefectures and will last until September 12.

This is in addition to the current state of emergency that is active in the prefectures of Tokyo, Ibaraki, Tochigi, Gunma, Chiba, Saitama, Kanagawa, Shizuoka, Kyoto, Osaka, Hyogo, Fukuoka, and Okinawa.