When I think about the vaccine side, I still wonder how long that will take. I don’t know how it works, will there just be almost immediate economies of scale t

When I think about the vaccine side, I still wonder how long that will take. I don’t know how it works, will there just be almost immediate economies of scale to vaccinate people? If vaccines will also be available in ‘waves’ as they are produced, then that must mean testing is some kind of a prerequisite to know who to give the vaccine to that needs it most - and who also may already be immune from exposure? It seems like the total cases —> 0 option is virtually unattainable in the near term (probably into 2021). Maybe with more cases being reported, we are aiming for 2) but actually going through 3).