The complexity of the distribution of such a vaccine on such a large scale will be a major bottleneck in a return to a society without imposed pandemic measures. A much less sexy and more human bottleneck, which permits of far more classes of failure of getting the virus to people well. The distribution is important work which we will see being the subject of much criticism. I hope everybody can keep their expectations in check. Getting working vaccines is incredibly important, but this is just the first step. There are no easy fixes - we'll be in this situation for the foreseeable future.