The US Food and Drug Administration on Wednesday announced a big change in the way doses of Pfizer-BioNTech’s COVID-19 vaccine can be handled. From now on, undiluted vials of the mRNA vaccine can stay at normal refrigerator temperatures for up to a month rather than the previous limit of just five days.
The change has the potential to significantly ease storage issues and promote the use of the highly effective vaccine, which has been hindered in some settings by its ultra-cold storage requirements.
For long-term storage, the vaccine still requires ultra-cold freezer temperatures—between -80°C to -60°C (-112°F to -76°F). But the vials can be transported and temporarily stored at normal freezer temperatures—between -25°C to -15°C (-13°F to 5°F)—for up to two weeks. According to yesterday’s update, the undiluted vials can then be thawed and kept at normal refrigerator temperatures—between 2°C to 8°C (35°F to 46°F)—for up to a month. Once the vials are diluted and ready for use, they must be used within six hours, according to the FDA’s detailed handling guide.