A contaminant found in a batch of Moderna Inc’s COVID-19 vaccines delivered to Japan is believed to be a metallic particle, Japanese public broadcaster NHK reported, citing sources at the Health Ministry.
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.
The NHK report published late on Thursday cited the Ministry as saying the particle reacted to magnets and was therefore suspected to be a metal.
Moderna has described it as “particulate matter” that did not pose a safety or efficacy issue.
The Health Ministry official in charge of vaccine matters was not immediately available when contacted by Reuters.
The Ministry has said the suspension is a precaution.
But the move prompted several Japanese companies to cancel worker vaccinations and the European drugs regulator to launch an investigation.
Spanish pharma company Rovi, which bottles Moderna vaccines for markets other than the United States, said the contamination could be due to a manufacturing issue in one of its production lines and it was conducting an investigation.
The Japanese government has not disclosed how many shots from the contaminated batch had already been administered.
Kyodo News reported at least 176 000 shots were administered, based on its own tally of figures reported by local municipalities.
