https://techcrunch.com/2021/02/19/pfizer-biontechs-covid-19-vaccine-just-got-a-lot-easier-to-transport-and-distribute/

The COVID-19 vaccine developed by Pfizer and BioNTech now has less stringent and extreme transportation requirements than it debuted with. Originally, the mRNA-based vaccine had to be maintained at ultra-low temperatures throughout the transportation chain in order to remain viable – between -76°F and -112°F. New stability data collected by Pfizer and BioNTech, which has been submitted to the U.S. Food and Drug Administration (FDA) for review, allow it to be stored at temps between 5°F and -13°F – ranges available in standard medical freezers found in most clinics and care facilities.

The vaccine should remain stable for up to two weeks at that temperature, which vastly improves the flexibility of its options for transportation, and last-mile storage in preparation for administration to patients. To date, the vaccine has relied largely on existing “cold-chain” infrastructure to be in place in order for it to be able to reach the areas where it’s being used to inoculate patients. That limitation hasn’t been in place for Moderna’s vaccine, which is stable at even higher, standard refrigerator temperatures for up to a month.