The use of over a million doses of the Moderna vaccine was suspended last week in Okinawa after Japanese authorities received alerts that the doses had been contaminated. The decision was taken when two men in the region died after being inoculated with the affected batch. While authorities are still investigating if there is a definite link between the two incidents, more contamination cases are being seen in other parts of the country.
Fresh reports coming from Reuters today states that yet another vial has been found to be polluted with what looks like mysterious black particles. The vaccine chaos unfolded when a pharmacist in the Kanagawa prefecture noticed the specks with his own eyes. According to the BBC, 3,790 people were administered with the contaminated vial before it was put on hold.
So far no other countries that approved Moderna have faced a similar situation and the local distributor, Takeda Pharmaceutical, has since reclaimed the vial for examination. Last week the company froze three batches which had around 560,000 vials for the same reason.
On 1 September, the company finally issued a statement outlining the possible causes for contamination after an initial investigation done by ROVI—the Spanish pharmaceutical company in charge of bottling the vaccine. Takeda stated on their website that the black particles in the vaccine were most likely the result of a manufacturing error. They explained:
The most probable cause of the particulate contamination identified in lot 3004667 was friction caused by the faulty installation of two metal parts in a module of the vaccine production line (a piece of equipment used in the vaccine dosing process).
The two parts are located in the same place. These two parts are the star wheel and the part that feeds the rubber stopper to the star wheel. It is believed that the parts were improperly positioned during the changeover of the production line prior to the production of lot number 300466.