The US Food and Drug Administration (FDA) has approved more ‘flexible’ storage of the Pfizer/BioNTech COVID-19 vaccine after receiving new stability data from the companies last week.
On 19 February, Pfizer/BioNTech submitted data to the FDA that demonstrates the stability of their mRNA-based COVID-19 vaccine at warmer temperatures.
This data showed that undiluted frozen vials of the vaccine can be stored at temperatures of -25°C to -15°C for up to two weeks – the temperatures commonly found in pharmaceutical freezers and refrigerators.
Prior to the FDA authorisation for the new temperatures, the label stated that the vaccine must be stored in an ultra-cold freezer at temperatures between -80ºC and -60ºC, where it can be stored for up to six months.
“Pfizer submitted data to the FDA to support this alternative temperature for transportation and storage. This alternative temperature for transportation and storage of the undiluted vials is significant and allows the vials to be transported and stored under more flexible conditions,” said Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research.
“The alternative temperature for transportation and storage will help ease the burden of procuring ultra-low cold storage equipment for vaccination sites and should help to get vaccine to more sites,” he added.
The agency said that the alternative temperature for storage of frozen vials does not apply to the storage of thawed vials of the vaccine before dilution – which can be held in a standard refrigerator for up to five days.
Pfizer will continue to ship the BioNTech-partnered vaccines in its ‘specially-designed’ ultra-cold shipping containers, that can also be used as temporary storage for up to 30 days.
The new flexible storage of the vaccine will alleviate some of the challenges Pfizer/BioNTech have been facing with the roll-out of the jab.
In the US, many healthcare facilities were unprepared for the ultra-low storage temperature of the vaccine, with some even resorting to acquiring special freezers to store the jab.
“It gives people more storage options, and more accessibility in locations that today may not be ordering the Pfizer vaccine,” Tanya Alcorn, vice president of Pfizer’s BioPharma Global Supply Chain told Time.
The new, warmer storage temperatures could also ease the roll-out of the vaccine in countries that lack the infrastructure to support the previous, ultra-low temperatures.
Responding to the stability data published earlier this week, a World Health Organization (WHO) spokesperson commented: “We are aware of reports of this and look forward to seeing the data. If proven correct, this could make roll-out of the vaccine easier in all countries, and particularly in low-income ones.”