This is good news, and we could all use some good news. But I feel like the focus on the death rate is partially obscuring the key issue. We don’t have a “death rate” problem yet. What we have is a “hospitalization rate” problem. Even if aggressive social distancing measures succeed in sharply limiting the number of people who get infected (in the short term), there are still going to be an unmanageable number of infected patients descending on U.S. hospitals over the next few weeks and months. And that’ll have a cascade effect. Doctors and nurses, many of whom lack proper safety equipment, will get sick and be sidelined or even die. (That’s not hypothetical.) People who need hospital treatment for conditions unrelated to COVID-19 will fall through the cracks, with some ending up dead. (That’s not hypothetical either.) And many who do need treatment for COVID-19 won’t get the quality of care they require to beat the disease, leading to more death among that group too.

The death rate is partly dependent upon the hospitalization rate, in other words. And we don’t need studies to grasp that. All we need to do is look at the overwhelmed health-care system in Italy, where the death toll is now higher than China’s (if you believe the official Chinese numbers). How do we solve the hospitalization rate problem ASAP? China can conscript labor to build and staff temporary hospitals overnight to increase capacity. We can’t.

Bear in mind too that even the revised Wuhan death rate is still many times higher than the rate for the common flu. If 10 million Americans were infected and the Wuhan death rate held, we’d be looking at 140,000 people dead. Flu season this year is expected to kill about a third that number at worst.

The study, published Thursday in the journal Nature Medicine, calculated that people with coronavirus symptoms in Wuhan, China, had a 1.4 percent likelihood of dying. Some previous estimates have ranged from 2 percent to 3.4 percent…

While the overall symptomatic case fatality rate was 1.4 percent, for people who were 60 and older it was 2.6 percent. That makes the older age group about five times more likely to die than people with symptoms who were 30 to 59 years old, whose risk of dying was 0.5 percent. For those under 30, it was 0.3 percent.

The risk of developing symptomatic infection itself also increased with age, about 4 percent per year for people aged 30 to 60, the study said. The authors estimated that people 60 and older were twice as likely to develop symptoms as people aged 30 to 59 and that people under 30 have about one-sixth the chance of developing symptoms from the infection. That suggests, as has other research, that many young people may be unknowingly infected and able to spread the virus to others.

We already have some data about COVID-19 hospitalizations in our own country via the CDC. Everyone’s well aware by now that young people are much less likely to die from the disease than older people are. Are they also less likely to be hospitalized, though? Hmmmm:

[O]f the 508 patients known to have been hospitalized, 38 percent were notably younger — between 20 and 54. And nearly half of the 121 patients who were admitted to intensive care units were adults under 65, the C.D.C. reported

In the C.D.C. report, 20 percent of the hospitalized patients and 12 percent of the intensive care patients were between the ages of 20 and 44, basically spanning the millennial generation…

The youngest age group, people 19 and under, accounted for less than 1 percent of the hospitalizations, and none of the I.C.U. admissions or deaths.

Teenagers are basically immune, in other words, but as you age out of that group your chances of having to compete for a hospital bed in an overwhelmed system begin to rise. On the other hand, we can’t draw any firm conclusions from this data about the relative likelihood of hospitalization by age. For one thing, the CDC didn’t look to see if patients had any preexisting conditions; comorbidities have been a key risk factor in Italy, so maybe it’s only younger people with underlying health problems who ended up in the ER. Beyond that, because our testing is so poor, we still have no idea how many people, especially younger people, are carrying this disease and experiencing zero symptoms. It may well be that half the local ICU patients with coronavirus are under age 65 — but it also may be that there are, say, 100 times as many people under age 65 who are walking around carrying the virus among the general population than there are senior citizens carrying it.

If that’s what’s happening then those spring-breaker bros are even more of a health threat than we thought. Tens of thousands of them might have gotten infected on Florida’s beaches and will remain blissfully unaware that they’re carrying the virus, only to bring it back home with them to their local community. Nice job by Ron DeSantis to finally shut down that petri dish two weeks after it would have helped to do so.

One of the authors of the new Wuhan study is Marc Lipsitch. He has a piece today in Stat responding to the column written a few days ago by Stanford epidemiologist John Ioannidis that I wrote about here. Ioannidis made the point that we’re taking some awfully draconian social and economic measures to try to choke off a disease about which we still know very little. We don’t know how many people have it; we don’t know how deadly it is; we don’t know how easily it might be treated. Gonna shut down the U.S. economy for that? Lipsitch counters with a point I made myself, though: We know enough to know that this isn’t business as usual. Ioannidis never mentioned what’s happening in Italy in his piece. Lipsitch does. Two things are already clear, he says:

First, the number of severe cases — the product of these two unknowns — becomes fearsome in country after country if the infection is allowed to spread. In Italy, coffins of Covid-19 victims are accumulating in churches that have stopped holding funerals. In Wuhan, at the peak of the epidemic there, critical cases were so numerous that, if scaled up to the size of the U.S. population, they would have filled every intensive care bed in this country…

Second, if we don’t apply control measures, the number of cases will keep going up exponentially beyond the already fearsome numbers we have seen. Scientists have estimated that the basic reproductive number of this virus is around 2. That means without control, case numbers will double, then quadruple, then be eight times as big, and so on, doubling with each “generation” of cases.

We can do aggressive social distancing or we can let our hospitals be completely, wildly overrun, says Lipsitch. (They’ll be partially overrun even with aggressive social distancing.) But that’s the choice facing us at the moment, while we think strategically about next steps. Don’t kid yourself into believing otherwise.

Gonna leave you with this, from an NYT reporter: