Japan has placed a batch of the Moderna vaccine on hold after a substance was found in a vial.
A pharmacist discovered several black particles in one vial of the vaccine.
Over 3,500 people had already received vaccinations from the batch, which has now been put on hold.
The news comes less than one week after Japan suspended the use of roughly 1.63 million Moderna doses due to contamination fears.
The pharmacist discovered black particles in the vial while checking for foreign substances before using the vaccine.
There is no evidence so far of any health hazards caused by the potentially contaminated vaccine.
Spanish pharmaceutical company Rovi, who bottles the vaccine, said that a manufacturing line in Spain could be the cause of the issue.
The company said they are currently conducting an investigation.
Japan’s vaccination roll out has been relatively slow, with just 50% of their population having received their first dose, while only 40% are fully vaccinated.