Vaccines are transported in a cold chain from the manufacturer all the way out to the last village on the end of tracks so poor only motorcycles can ride on them. The last part of that cold chain is off grid, using solar, diesel generators, ice packs, and kerosene fridges.
The first rule of operating an off grid cold chain is to always, always, always keep the freezer full to the top with ice packs.
The ice packs will of course be needed to pack coolers to distribute the vaccines, but they are also your backup system. A freezer filled to the brim with ice packs will be able to bridge a 3 or 4 day interruption in fuel (or failed generator, or burned up wiring, or security evacuation, or, etc, etc, etc), and save hundreds of thousands of dollars of vaccines from loss, not to mention possibly human lives.
The first rule of operating an off grid cold chain is to always, always, always keep the freezer full to the top with ice packs.
The ice packs will of course be needed to pack coolers to distribute the vaccines, but they are also your backup system. A freezer filled to the brim with ice packs will be able to bridge a 3 or 4 day interruption in fuel (or failed generator, or burned up wiring, or security evacuation, or, etc, etc, etc), and save hundreds of thousands of dollars of vaccines from loss, not to mention possibly human lives.
Ice rocks.