The contaminant found in a Japan-bound lot of Moderna Inc's Covid-19 vaccines is suspected to be a metallic powder, Japanese public broadcaster NHK reported, citing sources at the health ministry.
The report late Thursday cited the ministry as telling NHK that the particulate matter reacted to magnet and was therefore suspected to be a metal.
Japan on Thursday suspended the use of 1.63 million doses of Moderna's vaccine, more than a week after the domestic distributor received reports of contaminants in some vials.