tl;dr: We may have a method for lessening risk, but COVID is a new kind of horribleness. The world is not ever going completely back to the way it was.
It seems possible that we'd have a vaccine in place by April 2021, but everyone seems to forget how the influenza vaccine is only partially effective. It covers 60% of the strains for that year. Mutations cause a need for new vaccines every year, and they're still not entirely effective.
But influenza doesn't leave recovered patients with organ failure, as COVID appears to do. While some people are asymptomatic, and others suffer on the scale of a mild cold, and even people who suffer the more common, dreadful symptoms appear to recover in 2~3 weeks, there are a growing number of cases where people are sick for MONTHS. And there are cases where the organ damage to kidney, heart, liver, or lungs requires replacement organs.
We are going to need new safeguards and new behaviors, in addition to medical solutions.