Japan has suspended the use of about 1.63 million doses of the Moderna vaccine due to contamination.
The health ministry said “foreign materials” were found in some doses of a batch of roughly 560,000 vials.
Takeda Pharmaceutical, which sells and distributes the vaccine in Japan, said Moderna had put three batches on hold “out of an abundance of caution”.
It said an issue at a manufacturing contract site in Spain was the likely cause, but did not elaborate.
“To date, no safety or efficacy issues have been identified,” Moderna said, adding that it would work with regulators and Takeda to investigate the matter further.
There are no details of what the “foreign objects” are, but Takeda described it as particulate matter, after which it said conducted an emergency examination.