The big problem with transporting vaccines is the storage temperature. The mRNA technology behind BioNTech and Moderna has been in development for years and I'd be surprised if anyone can work out how to shift it above dry ice and freezer temperatures so quickly. Oxford, Janssen, and Sputnik V use older technology with refrigerator temperatures and I'd be even more surprised if they can be shifted to room temperature. So, the Third World need fleets of refrigerated lorries and GP surgeries with reliable electricity. I think most can achieve that.