Vaccine vials
Vaccine vials Olivier Fitoussi/Flash90

Japan has suspended use of around 1.63 million doses of coronavirus vaccine manufactured by Moderna, the Associated Press reports, after unused vials were found to be contaminated.

Japan’s Health Ministry noted that multiple vaccination sites had reported issues, without specifying the type of contamination, although it did assure citizens that no adverse health effects had been reported so far.

Moderna has now been asked to conduct an emergency investigation, with specific focus on certain production numbers that were apparently produced in Spain. There is currently no information on whether the affected doses may have been distributed in additional countries.

Around 43% of the Japanese population has been fully vaccinated to date, using vaccines produced by Pfizer and AstraZeneca as well as Moderna.