1. Invest in a huge rollout of free testing so that we know who is sick. The University of Washington set up a drive-through system so that certain people can be tested without contaminating a clinic; South Korea did the same. We urgently need “rapid tests” — offering results in minutes — and before long we will also desperately need tests to determine who has had the virus and now has immunity.

2. Cancel large gatherings in parts of the country where community transmission is occurring, as Gov. Jay Inslee has done in Washington State. Employers should encourage people to work from home where possible. Even with social distancing, more than one-third of Americans may eventually be infected (a worst case is that 70 percent become infected, as Chancellor Angela Merkel of Germany has cautioned for her country).

But lives will be saved by flattening the curve so that infections grow more slowly. We are much better off if 100 million Americans contract the coronavirus over 18 months rather than over 18 weeks, and this also gives scientists the chance to test treatments and develop vaccines, and to see if warmer weather helps. South Korea’s experience suggests that aggressive measures, well short of China’s, do help.

3. Expand telemedicine so that patients can get medical advice while staying home. The aim is for people to NOT go to a doctor’s office or E.R. unless necessary.

4. Plan for hospitals to be overwhelmed, as happened in Wuhan, China, and in Iran and northern Italy. Epidemiological models suggest that by late April we could have millions of Americans infected, and the danger is that people with other ailments die for want of care in the chaos. Several epidemiologists suggest that we could easily see 100 million infections of the new coronavirus in the United States, of which 5 or 10 percent might require hospitalization and 1 percent might need a ventilator. That could mean almost one million people needing ventilators just for Covid-19, though not all at the same time, yet we have only about 72,000 full ventilators in the United States.