The FDA on Thursday, 26 February, has relaxed the strict storage requirements for the Pfizer-BioNTech’s vaccine, allowing for its storage in temperatures found in regular pharmaceutical freezers (-20 degrees Celcius) for up to 2 weeks, reports TIME.
The news release by The Food and Drug Administration of USA also states that frozen vials of the undiluted vaccine may be stored in normal refrigerator temperatures (2 - 8 degrees Celsius) for up to 5 days.
This announcement loosens up a major restriction brought on by the earlier strict storage guidelines that required the Pfizer vaccine to be stored in ultra-low temperatures of -80 to -60 degrees Celsius.
The previous requirements posed a logistical problem for the storage and transportation of the vaccine, particularly in countries outside of the US, and in warmer countries like India.
Special deep freezers and shipping containers were developed by Pfizer that could keep the vaccine appropriately cold. And yet, this meant many locations (particularly outside of the US) opted out of the vaccine.
“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.”Peter Marks, M.D., Ph.D., 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 vaccines to more sites,” he added.
The FDA made the move after reviewing the latest data on the stability of the vaccines in warmer temperatures submitted by the companies, and has officially updated its ‘Fact Sheets for Health Care Providers Administering Vaccine,’ with the new guidelines.
The vaccines will continue to be shipped in ultracold temperatures of below -60 degrees celsius, in special freezers but once received, facilities and hospitals will now be able to place them and transport them in a regular pharmaceutical freezer for up to two weeks, and once thawed, the undiluted doses can be stored and transported in regular refrigerators for up to 5 days.
How Does It Compare to Other Vaccines?
The new guidelines put the storage requirements for the Pfizer vaccine at par with the other vaccines approved for emergency use in India (Oxford/AstraZeneca’s Covishield and Bharat Biotech’s Covaxin).
The storage temperature requirements for other authorised vaccines are:
- Pfizer/BioNTech: -70 degrees Celsius
- Moderna: -25 to -15 degrees Celsius
- Oxford/AstraZeneca (Covishield): 2- 8 degrees Celsius
- Bharat Biotech (Covaxin): 2 - 8 degrees Celsius
- Johnson & Johnson (Jenssen): 2 - 8 degrees Celsius
- Sputnik V: 2 - 8 degrees Celsius
The reason Moderna and Pfizer/BioNTech vaccines need to be kept in ultra-low temperatures is because of the new messenger RNA (mRNA) technology based on which the vaccines have been developed.
The mRNA molecules are protected by a layer of fat particles that degrade quicker in warmer temperatures.
The vaccine was granted authorisation for emergency use by the FDA back in December, making it the first COVID-19 vaccine to be greenlighted in the US.
(Written with inputs from TIME and ScienceAlert.)