I think you are jumping the gun a bit, on vaccines. Nobody is giving them out to people, other than in Phase III clinical trials. China did announce they were giving them to their military, but that is actually a clinical trial too, with a vaccinated arm and a control arm. In fact a few Phase III trial enrollments are going on now. If you look at the end date of these trials, they are a long way off in 2021 or even 2022.

It is possible that some will work so well, and pick a good place to run the trial like Brazil, that they will announce preliminary results by December. If the placebo arm gets Covid-19 at the same high rate as the general population in the area, and the vaccinated arm gets low to none, then we have a winner.