The latest incident comes from Kanagawa, a coastal prefecture just south of Tokyo. The whole lot was put on hold after a pharmacist in the region saw several black particles in one vial of the batch.
Takeda Pharmaceutical Co Ltd, a drugmaker distributing Moderna vaccines in Japan, said some 3,790 people already received shots from the suspended lot.
Moderna said earlier no safety or efficacy issues have been identified from the issue. Two men in their 30s died this month several days after receiving a second dose from one of the suspended batches. No causality link between the injections and the deaths has been established so far.
Kanagawa’s incident comes as the country has already suspended more than 2.6 million doses earlier this month over similar concerns.
Okinawa, a prefecture comprising more than 150 islands in Japan, announced in a statement on Aug. 29 it had suspended the use of Moderna vaccines at a major vaccination center in the city of Naha after “foreign substances were spotted,” The Japan Times reported.
Also in Gunma prefecture, located north of Tokyo, contaminated lots were paused over similar concerns, though an official noted that they will continue distributing “lots that are not affected by the incident.”
According to a Kanagawa official, Takeda had collected the vial with the suspected contaminant. The distributor has not immediately responded to comment on the incident.
Japan’s health ministry, citing an investigation by Takeda, said on Wednesday that the vial sent to Kanagawa was from a different lot than the other lots, and rubber stopper material appears to have gone into it during the manufacturing process.
Moderna also announced in a statement that contamination could be due to a manufacturing issue on one of the production lines at its contract manufacturing site in Spain, operated by Madrid-based Rovi.
A spokesperson for Rovi—which bottles Moderna vaccines for markets outside of the United States—said they launched an investigation into a prior incident involving 1.63 million doses, but they haven’t released an update on the investigation so far.
The Spanish plant was instructed by the European Medicine Agency (EMA) on Aug. 27 to continue producing the vaccines after officials did not find reasons to seek a temporary suspension of production after an initial assessment.
Officials said an unknown number of doses from the previously affected lots have been administered.
Moderna confirmed in an Aug. 28 joint statement they have been notified by Takeda and launched an investigation, saying they are working “expeditiously” with the Japanese company to address the incidents.
As of Sept. 1, 16,080 Japanese citizens have died from COVID-19 since the start of the pandemic, according to health officials. A large part of the country has been placed under strict measures in response to the CCP (Chinese Communist Party) virus, which causes COVID-19.
More than 1,000 people in Japan have died after receiving a COVID-19 vaccine, including 11 from Moderna’s. The country’s health ministry said they haven’t established a causality link between the injections and the deaths.
Reuters contributed to this report.