The impurities discovered in batches of the anticovid vaccine from Moderna in Japan turned out after analysis to be metallic particles, said on Wednesday the American company, which assures that the incident did not pose "an excessive risk for the safety" of consumers.
Japan announced last week to suspend the use of vaccines from three batches, representing more than 1.6 million doses, after reports from several vaccination centers finding foreign bodies in vials of vaccine.
The installation of plugs probably involved
Analyzes were carried out by Moderna on one of the batches in question: the particle found was found to be "stainless steel", according to a joint statement with the Japanese pharmaceutical group Takeda, which imports and distributes the vaccine in the Japanese archipelago. The problem stems from a production line of a subcontractor in Spain, Rovi, which produces Moderna's vaccines for markets outside the United States.
According to the investigation carried out by Rovi, "the most probable cause" is "friction between two pieces of metal installed in the plugging module of the production line, due to improper assembly", explains the press release. . The doses of these three lots will be recalled to be withdrawn from the market from Thursday, according to the press release. But "the rare presence of stainless steel particles in the vaccine (...) does not pose an excessive risk for patient safety", he assures, specifying that this type of metal is frequently used in the food industry. , or for heart valves.
"Metal particles of this size injected into a muscle could cause a local reaction, but should not a priori cause other serious reactions beyond the site of injection," write Moderna and Takeda.
“Injection of the particles identified in these batches in Japan is not expected to result in an increased medical risk,” they conclude.
A fortuitous link with the two deaths?
The Japanese health ministry also announced last week the opening of an investigation to determine the cause of death in August of two men, who received a dose of vaccine from one of the three suspended batches.
According to the press release from the two companies on Wednesday, "there is no evidence" that these two deaths are linked to the administration of the vaccine. "The link is currently considered fortuitous," Moderna and Takeda write, calling for the investigation to continue. Japanese regions have since suspended injections of the vaccine after the discovery of other contaminated batches, which Wednesday's press release does not mention.