Building out the capacity to manufacture and distribute ten billion doses of new vaccines as quickly as we can validate their safety and efficacy would also be quite the feat.

It's nice for a first-world citizen that we were getting vaccinated against a new disease 12-18 months after it was first discovered, but with a big enough supply chain we could potentially be aiming to finish a world-wide vaccination campaign in 6-12 months, before we begin running up against the limits of our current methodologies for clinical trials.