Nearly one-fifth of the population has received at least a first dose of vaccine, according to the latest Virus Tracking report from the Insights Collective. As the vaccines continue to roll out, they will reinforce a long, downward trend in Covid cases that began in early January. Nationally, new cases are approaching 50,000 a day, on average, down from nearly 300,000 daily cases. Hospitalizations have also declined, by roughly 70 percent. With many states loosening Covid restrictions, it appears that winter resorts will avoid a Covid shutdown this spring. But some resort destinations have seen recent increases in the number of infections, including Aspen, and Vail, Colo., and Miami, Fla. That’s a danger sign with spring break on the horizon.