Contaminant in Japan's Moderna vaccines suspected to be metallic particles: NHK

The Japanese government has not disclosed how many shots from the contaminated batch had already been administered. PHOTO: EPA-EFE

TOKYO (REUTERS) - A contaminant found in a batch of Moderna'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 (Aug 26) 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.

An official at the health ministry said the identity of the contaminant has not been confirmed.

News of the contaminant could provide a fresh setback for Japan's inoculation drive as it struggles to persuade many - particularly among the youth - to get vaccinated.

On Friday, eight more prefectures entered a state of emergency, bringing a total of about 80% of Japan's population under Covid-19-related restrictions. The government reported nearly 25,000 new infections and severe cases at a record 2,000 for Thursday.

The ministry has said the suspension of the Moderna batches was 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.

Moderna put the lot in question and two adjacent ones on hold.

Remote video URL

A separate health ministry official said it would take "some time" to confirm how many shots from the contaminated batch had already been administered in Japan. Kyodo News reported that at least 176,000 shots have been used based on its own tally of figures reported by local municipalities.

So far, about 54 per cent of Japan's population has received at least one dose.

Join ST's Telegram channel and get the latest breaking news delivered to you.