An investigation found that a batch of Moderna COVID-19 vaccine in Japan was contaminated with stainless steel.
The Japanese distributor of the jab, Takeda Pharmaceuticals, told Newsweek in a joint statement with Moderna that contamination is unlikely to cause any medical risks.
Takeda announced on August 26 that it would suspend the use of three batches of 1.63 million doses of vaccine. Previously, there were reports that foreign particles were found in vials at the vaccination site.
An investigation by Rovi, a Spanish pharmaceutical company involved in bottling vaccines, found that the substance in a batch was most likely caused by friction between two pieces of metal in the plugging module of the production line, and the module was not set up correctly.
The statement said: "The two pieces are the star wheel and the plug feeding device, and the latter feeds the plug into the star wheel."
The statement stated that only one of the suspended batches was contaminated, and Rovi has taken measures to correct and prevent future accidents.
The statement said: "The rare stainless steel particles in the Moderna COVID-19 vaccine will not pose an undue risk to patient safety," and pointed out that this steel is commonly used for items such as heart valves and joint replacements.
It added that metal particles of this size injected into the muscle “may cause local reactions, but are unlikely to cause other adverse reactions beyond the injection site.”
The statement stated that there is no evidence that the two deaths after vaccination were related to vaccination.
"This relationship is currently considered a coincidence. It is important to complete a formal investigation to confirm this."
After a foreign body was found in an unused vial, Moderna injections in other areas were temporarily stopped this week, and when the needle was inserted incorrectly, the rubber stopper of the vial was partially detached.
According to the BBC report on Wednesday, a batch of Moderna was suspended in Kanagawa Prefecture after a pharmacist found black particles in a vial of vaccine.
On Tuesday, Japanese Minister of Health Tamura Norihisa stated that the foreign body found in the jab in southern Okinawa prefecture was caused by a needle that was inserted into a vial by mistake, which caused rubber fragments to enter the vaccine.
As Japan is fighting a wave of COVID infections, the number of daily infections in August exceeded 25,000 for the first time. Reuters quoted the national broadcaster NHK as reporting that on Wednesday, there were 20,031 new cases across the country, of which 3,168 were recorded in Tokyo.
Less than half of the population (45.4%) has been fully vaccinated, lagging behind the rates of several developed countries.
Update 9/01/21 11:56 AM Eastern Time: This article has been updated with Takeda and Moderna’s statements and more information.
You have 4 free articles this month
Enjoy Newsweek’s free newsletter with 5 million readers