Wendover did a nice video[0] on this topic month ago, explaining how UPS/FedEx/DHL/… are already massively upscaling their cold chain infrastructure. Retrofitting planes, building giant freezers in transport hubs.
[0] The Greatest Logistics Challenge Ever - https://www.youtube.com/watch?v=byW1GExQB84
One thing that I found interesting was how they identified today's announcement of the BNT162b2 vaccine candidate (back in September) as one that would require the massive investment in cold chain infrastructure. They also highlight Pfizer's engineering of a separate series of cold boxes that would keep the vaccine at temperature for up to 10 days, thereby enabling it to be shipped through standard logistics networks. Great stuff.
In the UK, the NHS are generally on top of things like this, so it should not happen in most cases.
If there are 7 billion people and 1 billion doses in the next year, it's going to be awkward.
Yeah, this alone is bad news.
Last year my parents got a two-dose shingles vaccine. The two doses are supposed to be separated by two to six months. My parents struggled to find their second doses in the window. Apparently there was limited supply and no one had the foresight to reserve second doses when people received their first, or even to prioritize second doses over first.
The covid vaccine will have much more demand and apparently a tighter window, and our health system isn't exactly well-coordinated right now, so I anticipate a lot of people will be unable to get the second dose with the proper timing.