Japan's health ministry has, reportedly, detected metallic particles in some doses of Moderna's vaccine that were sent to the country last week. Moderna previously stated that the "particulate matter" found in some vials was not harmful and they do not affect the vaccine's efficacy.
Sources with the ministry, as reported by NHK, said researchers found that the contaminants had reacted to magnets, which means they may be metallic in nature. Health ministry officials have asked the public not to speculate on what the contaminants are, as they have not yet been confirmed.
Following reports of the alleged contamination, Japan had suspended the use of 1.63 million doses of the company's vaccine. Most of the doses were already distributed to 863 vaccination centers around the country. The vaccines were, reportedly, imported to Japan by local distributor Takeda Pharmaceuticals.
Ministry officials said the suspension of the use of Moderna's vaccines is a necessary precaution. The ministry along with drug regulators in Europe has launched an investigation into the matter.
Officials said they are still actively working to determine how many of the contaminated shots were administered to people in Japan. Finding that out would "take some time," officials said.
A report from Kyodo news estimated that 176,000 doses of Moderna's vaccine may have been administered based on its own tally and reports from local government offices.
Rovi, the Spanish company that bottles Moderna's vaccine for other markets outside of the U.S., said that it will also be conducting an investigation. The company said the contamination could be the result of a manufacturing issue on its production line but it has yet to prove if this was the case.
The suspension of the use of Moderna's vaccine is expected to be a major setback in the country's vaccination drive. The country is still struggling with a new wave of the coronavirus, fueled primarily by the more contagious Delta variant. Several Japanese companies have announced that they will be canceling worker vaccinations in light of the news.
Around 80% of Japan's population is still under strict COVID-19 restrictions due to rising cases. Eight more prefectures had entered into a state of emergency Friday. On Thursday, the country reported a daily record of 2,000 new cases.