Covid vaccine stored incorrectly potentially due to Celsius-to-Fahrenheit error

[pranavjoneja]

Pfizer's covid vaccine is supposed to be stored and transported at -70˚C, but some batches ended up at -92˚C.

-92˚F is quite close to -70˚C so this smells a lot like an error due to unit conversion. This "anomaly" happened in two separate instances in California and Alabama

(-92˚F - 32) x (5/9) = -68.8˚C

(-70˚C x (9/5)) + 32 = -94˚F

Source: https://www.cnbc.com/2020/12/16/covid-vaccine-us-quarantines-pfizer-shipments-in-california-alabama-after-transit-anomaly.html

[pwg]

Question: Is the storage temperature a specific value, or is it an "at least X or below" value?

I.e., does -92˚C damage the vaccine in any way?