What percentage of a population must be vaccinated before any kind of vaccine mandate is lifted? Public-health experts don’t quite agree on a number. Figures from 70 to 80 percent, or even higher, have been floated. Ali Mokdad, a professor of health-metrics sciences at the University of Washington, in Seattle, says he would like to see 80 to 85 percent of a population vaccinated before any sort of existing restrictions are lifted. Arguing that a winter uptick in coronavirus cases is still possible, he told me that vaccine mandates for indoor, public venues should remain in place until at least the spring…

The goal, public-health experts say, is reaching the point where hospitals are never overwhelmed with coronavirus patients again.

“My hope is we get to a place where, through vaccination coverage and through infections of the unvaccinated, we have a high level of protection against hospitalization,” Denis Nash, an epidemiologist at the City University of New York, told me. “At some point we have to move on, right?”

It’s reasonable to ask, as 2021 draws to a close: When will that be? Unlike in previous phases of the pandemic, public-health officials, politicians, and even members of the media seem to have little will to explain to millions of people what normalcy might look like. This is understandable for the time being. In the past, localities have relaxed various shutdowns and mandates, only to encounter a new wave of the coronavirus. No one wants to take another gamble and lose.