[Thread] 1. SA will be getting Pfizer jabs to use in #VaccineRolloutSA. Those jabs need to be stored in special freezers at -70 degrees Celsius. We don't have many of those freezers. So how will SA cope?

2. #Mkhize: Pfizer is sending its #CovidVaccines to SA in packaging that allows for the jabs to remain stable for a certain period until they get to a freezer. We've also had companies offering us access to the special freezers required so we can store the jabs safely.

3. Here's more background on the challenges with maintaining the cold chain with Pfizer jabs (some of these challenges have now been addressed with packaging that keeps the jabs at the right temp and more freezers that have become available). https://bit.ly/3q8UFHs 

4. So how exactly is Pfizer helping countries to store their jabs correctly? First of all, they have a "just-in-time" system: They ship frozen vials to countries as close as possible to the date of use. https://bit.ly/2LEDL4E 

5. The Pfizer jabs arrive in specially designed, temperature-controlled thermal shippers that use dry ice to maintain the recommended storage temperature of -70°C for up to 10 days while they're unopened (so there's time to get them to vaccination sites). https://bit.ly/2LEDL4E 

6. When a country receives Pfizer jabs, they have a few options for storage. The first option is ultra-low-temperature freezers, which are commercially available and can extend shelf life for up to 6 months (but most countries don't have enough of these). https://bit.ly/2LEDL4E 

7. Pfizer also uses thermal shippers, in which doses will arrive. The shippers can be used as temporary storage units by refilling them with dry ice every 5 days for up to 30 days of storage. https://bit.ly/2LEDL4E 

8. After storage for up to 30 days in a Pfizer thermal shipper, vaccination centres can transfer the vials to normal frigdes (2-8°C ) for a total of up to 35 days. Once thawed and stored under 2-8°C conditions, the vials cannot be re-frozen or stored under frozen conditions.