A true endpoint will come when a vaccine or therapy is discovered, tested, manufactured and distributed widely enough to protect a large share of the population, in addition to the point when sufficient people have recovered from sickness to possess natural immunity against a reinfection. But a vaccine could be a year to 18 months away, at least; and President Trump’s optimism at a news conference Thursday notwithstanding, antiviral drugs are hard to develop, even on a crash basis.

In the meantime, the goal must be to “flatten the curve,” or suppress the extent of infection enough to avoid massive overload on hospitals, as already happened in Italy. This might take two or three months, judging by China’s experience. That brings us to summer. If heat and humidity don’t impede the virus, what then? A study published this week by the Imperial College London, based on modeling, warned that if the first suppression measures are relaxed too soon or for too long, “we predict that transmission will quickly rebound.” Hopefully, some people who were sick will recover with natural immunity. But a large chunk of the population will remain as vulnerable in August as they are today.

Is it realistic to keep in place all the strict regimens for a year or 18 months? In a second phase, the public will be fatigued and under severe economic stress. Many people may be tempted to break the routine or take risks. One of the trickiest aspects of the coronavirus is that people can be contagious when they are not yet showing symptoms. The pandemic could come roaring back. Now that China is starting to reopen somewhat, it will be instructive whether a second wave of infection shows up.

AD

AD

Scientist Trevor Bedford of the Fred Hutchinson Cancer Research Center suggests the right approach then will be the method South Korea used effectively in the first phase: exhaustive testing, separating and isolating the sick, and tracing contacts. If those who are ill can be contained, he suggests, through a massive testing program, augmented by cellphone locating to alert those who might be exposed, transmission of the virus might be interrupted. Moreover, he suggests, those who recover could return to work and help keep society functioning. Of course, the United States has been woefully behind at testing from the outset, so Mr. Bedford’s plan would require a real turnabout.

We must not let a second wave take us by surprise.

Read more: