Several thousands of doses of the COVID-19 vaccine had to be returned to Pfizer due to an “anomaly” that caused storage temperatures to plunge during shipment, officials said Wednesday.
The trays — which contain 975 doses each — were being closely monitored en route to California and Alabama when the temperature dropped from minus 80 degrees Celsius to minus 92 degrees, according to Gen. Gustave Perna, the head of Operation Warp Speed.
Pfizer’s vaccine must be stored in ultra-cold freezers at minus 70 degrees Celsius but it is unclear how the vaccine reacts to temperatures much lower than that.
“We locked those trays down,” said Perna at a press briefing. “They never left the truck. We returned them immediately to Pfizer and we sent immediate shipments to replace those two trays.”
He said two trays arrived in two separate locations in California and two more went to Alabama.
Perna added that the Food and Drug Administration and Pfizer are now working on determining whether the “anomaly” rendered the vaccines unsafe.
“We’re taking no chances,” he said.
He said officials are still “learning but the key is we can see ourselves and we were able to take action.”
The COVID-19 vaccine by Pfizer and German company BioNTech began rolling out in the US this week, following approval from the FDA for use.
