This is the editor's letter in the current issue of The Week magazine.

By Memorial Day, says Vice President Mike Pence, "we will have this coronavirus epidemic behind us." In the warmth of summer, he and other sunny optimists predict, the virus will vanish like magic. By fall, the economy will come roaring back in a "V-shaped" recovery, and the past two months will all seem like a bad dream. Wouldn't it be lovely? When faced with a monu­mental crisis, optimism can be ­helpful — but magical thinking, not so much. It can lead to reckless behavior and disappointment. There is no reason to expect the virus to disappear in May or June or any time in 2020, says ­infectious-­disease specialist ­Michael Oster­holm, who's been urging the world to prepare for a pandemic since 2005. "This first wave of illness," he told CNN this week, "is just the beginning of what could very easily be 16 to 18 months of substantial activity of this virus around the world, coming and going, wave after wave."

That's a reality we're going to have to adapt to, Osterholm and other scientists say. They acknowledge we can't remain in lockdown indefinitely, but warn that as states loosen restrictions, the number of cases will start climbing again. This coronavirus is highly contagious, spreading easily through the air and touched surfaces; without social distancing, one infected person gives the virus to about three others. Oster­holm's math tells him that the virus will eventually infect at least 50 percent of the population, or roughly 150 million Amer­i­cans. About 80 percent will have mild or no symptoms, but assuming a fatality rate of just 0.5 ­percent — which is much lower than now ­observed — at least 800,000 Americans will die over 18 months if there is no vaccine or effective treatment. (Herd immunity would require 70 percent to be infected, and much higher death tolls.) These grim numbers, Oster­holm concedes, are just educated guesses. But he is certain of this: "As a country, we are utterly unprepared for the marathon ahead."