Here’s the grimmest version of life a year from now: More than two million Americans have died from the new coronavirus, almost all mourned without funerals. Countless others have died because hospitals are too overwhelmed to deal adequately with heart attacks, asthma and diabetic crises. The economy has cratered into a depression, for fiscal and monetary policy are ineffective when people fear going out, businesses are closed and tens of millions of people are unemployed. A vaccine still seems far off, immunity among those who have recovered proves fleeting and the coronavirus has joined the seasonal flu as a recurring peril.