Assuming this New Scientist story is accurate, this is momentous news. Albeit still totally speculative.

If you read this post or this post, you know the background here. The great unknown with coronavirus right now is how many people are infected. Nearly everything depends on that — the death rate, the hospitalization rate, how long people need to lock down, how long the crunch on hospitals will last. There are some basic things that don’t depend on it. Hospitals will be overwhelmed for some period; thousands will die; social distancing is helping to slow the rate of infection, which means more severely ill people can get quality care.

But the big-picture question, “How soon can we get back to normal?”, rests heavily on knowing how many people have been infected. And amazingly, despite the global freeze on human activity, we just … don’t know. We and other countries are taking the “better safe than sorry” approach at phenomenal economic cost, in the belief that this disease is just getting started spreading through the population. If so, we have months of misery ahead of us. We need extreme social distancing now and will have to maintain some social distancing measures well into next year to control the rate of infection. Hospitals will be battlefields for the rest of 2020 and beyond, even with the curve flattened a bit. We’ve only just begun to ascend that proverbial curve. It’ll be a long haul.

That was the contention of the Imperial College model co-authored by epidemiologist Neil Ferguson that convinced Boris Johnson’s government to start locking down the country. It was picked up everywhere, including here, and remains the model being followed by world governments. If this disease is just getting started, we need to take extreme measures to start putting out the fire before it burns up the whole world.

There’s another model, though. That one comes from the University of Oxford and contends that coronavirus has already spread much further than everyone thinks. We’re not starting our ascent up the epidemiological curve; we started many weeks ago and are already well on our way to the top, which means infections should peak soon-ish and then begin to fall, never to peak the same way again. In this model, the virus is much more contagious but much, much less lethal than anyone realizes. Hospitals are getting crushed right now because the total number of infected people across the population is so enormous that even the tiny sliver of severe cases in that group is enough to overload an ICU. Nearly everyone shakes the disease off with few or no symptoms, except for a very unlucky few.

If the New Scientist story is correct, Ferguson — an author of the Imperial College worst-case scenario — is swinging around towards (but not all the way to) the Oxford view. It might not kill 500,000 or two million people, he now says. It might kill more like … 20,000.

The UK should now be able to cope with the spread of the covid-19 virus, according to one of the epidemiologists advising the government…

He said that expected increases in National Health Service capacity and ongoing restrictions to people’s movements make him “reasonably confident” the health service can cope when the predicted peak of the epidemic arrives in two or three weeks. UK deaths from the disease are now unlikely to exceed 20,000, he said, and could be much lower.

The need for intensive care beds will get very close to capacity in some areas, but won’t be breached at a national level, said Ferguson. The projections are based on computer simulations of the virus spreading, which take into account the properties of the virus, the reduced transmission between people asked to stay at home and the capacity of hospitals, particularly intensive care units…

New data from the rest of Europe suggests that the outbreak is running faster than expected, said Ferguson. As a result, epidemiologists have revised their estimate of the reproduction number (R0) of the virus. This measure of how many other people a carrier usually infects is now believed to be just over three, he said, up from 2.5. “That adds more evidence to support the more intensive social distancing measures,” he said.

It’s more infectious than thought, it seems, which means the population of people who have it is larger than thought. Which means the virus is less lethal than thought. How much less remains to be seen. The Imperial College’s own news item about Ferguson’s presentation adds: “Ferguson explained that while there was some uncertainty, if current measures work as expected, then intensive care demand would ‘peak in approximately two to three weeks and then decline thereafter’.”

Could that be all there is to this? One or two horrendous months, and then a recovery as the population acquires herd immunity? You wouldn’t want to gamble on that right now by reopening the economy; the cost in blood and treasure if you lost that gamble would be fantastically large. Ferguson, in fact, thinks the new data indicating that the virus is more contagious than thought also strengthens the argument for aggressive social distancing: The next few months will be ugly no matter which model is right so flattening the curve will help make them more manageable. He also doesn’t agree with the Oxford model’s assumption that very few people who get coronavirus need to be hospitalized, saying, “I don’t think that’s consistent with the observed data.” If he’s right about that, that a small number will die but a significantly larger number will need to be hospitalized, then we still have a crisis even if it’s not an apocalyptic one. Many COVID patients who might be saveable if they can get ICU treatment will die if hospitals are too crowded to provide it. Some non-COVID patients who are saveable will die of their ailments because there’s a shortage of doctors who can see them in a timely manner.

Millions of lives and trillions of dollars in lost wealth depend on knowing whether the Imperial College model or Oxford model is closer to the truth. The only way to know is to start antibody testing on random samples of the population. You would think more effort globally would be involved in that right now. You would also expect to be hearing lots more about it from Trump, since the only hope of an early exit from this catastrophe would be discovering that the Oxford study is right, that most people have already contracted the disease and shaken it off without batting an eye. Until those tests are done, we’re fumbling around with circumstantial evidence like this:

The COVID Symptom Tracker, created by scientists at King’s College London, was downloaded around 650,000 times in the first 24 hours after it launched on Tuesday.

By today it had been signed up to by 1.25million people and has become the third most popular download in the UK’s App Store, with some 50,000 new users per hour.

Analysis of the first 650,000 users found that 10 per cent of them have had the symptoms of the coronavirus, which causes fever, coughing and tiredness…

If its infection rate of one in every 10 people is applied to the UK’s population of 66million, that could mean 6.6m or more have already had the illness which has sent the world into hiding.

Fever, cough, and fatigue can be caused by all sorts of diseases, of course. Not everyone who’s experiencing those symptoms has COVID-19. But if a few million do, that would vindicate the Oxford study’s suspicions that the virus has already spread much further than we know and it’s fatal in only a few hundred cases per million. Can we get a scientific answer to this question, please, before we lock down for several more months and 25 million people are out of work? Most Americans are prepared to do that if need be (or at least that’s what they say right now) but the economic toll would be grievous. Why isn’t antibody testing the feds’ tippy-top priority in guiding the government response going forward? We’re flying blind until we know how many people are infected.

In lieu of an exit question, read this story about antibody testing being prepared by Mt. Sinai in New York. The other great virtue of doing widespread testing of this sort, especially if lots of people have already been infected, will be identifying them so that they can immediately return to the work force. Assuming that infection grants a person durable immunity going forward, potentially millions of people would be safe to get back on the job soon-ish. Trump’s demand to reopen for business would be much less dangerous, especially if that effort begins with those have already had COVID-19 and shaken it off.

Update: I’ll have a separate post on this later, but here’s Ferguson himself insisting that we’ve all misunderstood.

2/4 -This is not the case. Indeed, if anything, our latest estimates suggest that the virus is slightly more transmissible than we previously thought. Our lethality estimates remain unchanged.

— neil_ferguson (@neil_ferguson) March 26, 2020

4/4 – Without those controls, our assessment remains that the UK would see the scale of deaths reported in our study (namely, up to approximately 500 thousand).

— neil_ferguson (@neil_ferguson) March 26, 2020