This story first appeared at ProPublica. ProPublica is a Pulitzer Prize-winning investigative newsroom. Sign up for The Big Story newsletter to receive stories like this one in your inbox.
The Pfizer vaccine is unusually difficult to ship and store: It is administered in two doses given 28 days apart, has to be stored at temperatures of about minus 100 degrees Fahrenheit and will be delivered in dry ice-packed boxes holding 1,000 to 5,000 doses.
Most doctors’ offices, even most hospitals, don’t have deep freeze facilities to manage these temps.
I can get dry ice (sublimation temperature -110F) literally at my supermarket. There are real distribution problems, but people have a wildly incorrect view of how many facilities can manage temperatures in this range.
The five-days-in-a-fridge tidbit, which was news to me, is also a big deal.
I just checked my state and we are fine, of course. We have a plan, and it makes sense. So I’m fine either way, once Biden is in, or even if Trump blocks him, with secession. Motherfuckers.
Which is why Pfizer is handling distribution exclusively (they do not trust the Feds, and have their integrity to maintain). They are shipping in “dry ice suitcases” (-75C) from distribution points that can last for up to 10 days.
Look for run up in stocks of ultra-low double cascade freezer companies that go down to -80C.
OH MY !! This is a logistical “Manhattan Project” - and no facet of the Trump administration has demonstrated the ability to organize and manage anything remotely close to the scale of this
administered in two doses given 28 days apart
has to be stored at temperatures of about minus 100 degrees Fahrenheit
will be delivered in dry ice-packed boxes holding 1,000 to 5,000 doses.
These cartons can stay cold enough to keep the doses viable for up to 10 days
I’m having a hard time crediting the technical requirements here. I would guess this vaccine has got to be delivered in some kind of injection-ready buffered aqueous solution, and such things freeze solid at or close to 0 degrees C. I’m trying to imagine what meaningful degradation would happen in the crystalline phase near this temperature, but not at -80C. How could anything that labile ever survive warming to ambient and then body temperature?
A lot of deep-freeze storage at dry ice or liquid N2 temperatures amounts to insurance–a buffer against momentary exposure to heat during multi-modal shipping and warehousing. I have to wonder if that’s the case here.
The way it was explained to me was that aqueous solutions do not freeze homogenously at 0C or -20C or -40C. Pockets of freeze-effect acid form and concentrate that can degrade sample. Flash-freezing in liquid N2 and -80C storage eliminates these pockets, thus eliminating sample degradation.
Thank you. I had trouble finding a technical discussion. The explanation supports the need for flash freezing with liquid nitrogen etc, but it isn’t immediately clear to me why you couldn’t then store the frozen vaccine at a less extreme temperature. As long as the solid phase is maintained, the homogeneity should persist.