Twitter thread >> https://mobile.twitter.com/jeremycyoung/status/1239975682643357696
We can now read the Imperial College report on COVID-19 that led to the extreme measures we've seen in the US this week. Read it; it's terrifying. I'll offer a summary in this thread; please correct me if I've gotten it wrong.
The Imperial College team plugged infection and death rates from China/Korea/Italy into epidemic modeling software and ran a simulation: what happens if the US does absolutely nothing -- if we treat COVID-19 like the flu, go about our business, and let the virus take its course?
Here's what would happen: 80% of Americans would get the disease. 0.9% of them would die. Between 4 and 8 percent of all Americans over the age of 70 would die. 2.2 million Americans would die from the virus itself.
It gets worse. People with severe COVID-19 need to be put on ventilators. 50% of those on ventilators still die, but the other 50% live. But in an unmitigated epidemic, the need for ventilators would be 30 times the number available in the US. Nearly 100% of these patients die.
So the actual death toll from the virus would be closer to 4 million Americans -- in a span of 3 months. 8-15% of all Americans over 70 would die.
How many is 4 million people? It's more Americans than have died all at once from anything, ever. It's the population of Los Angeles. It's 4 times the number of Americans who died in the Civil War...on both sides combined. It's two-thirds as many people as died in the Holocaust.
Americans make up 4.4% of the world's population. If we extrapolate these numbers to the rest of the world (warning: MOE is high here), this gives us 90 million deaths globally from COVID-19, in 3-6 months. 15 Holocausts. 1.5 times as many people as died in all of World War II.
Now, of course countries won't stand by and do nothing. So the Imperial College team ran the numbers again, this time assuming a "mitigation" strategy: all symptomatic cases in the US in isolation. Families of those cases quarantined. All Americans over 70 social distancing.
This mitigation strategy is what you've seen a lot of people talking about when they say we should "flatten the curve": try to slow the spread of the disease to the people most likely to die from it, to avoid overwhelming hospitals.
And it does flatten the curve -- but not nearly enough. The death rate from the disease is cut in half, but it still kills 1.1 million Americans all by itself. The peak need for ventilators falls by two-thirds, but it still exceeds the number of ventilators in the US by 8 times.
That leaves the actual death toll in the US at right around 2 million deaths. The population of Houston. Two Civil Wars. One-third of the Holocaust. Globally, 45 million people die: 7.5 Holocausts, 3/4 of World War II. That's what happens if we rely on mitigation & common sense.
Finally, the Imperial College team ran the numbers again, assuming a "suppression" strategy: isolate symptomatic cases, quarantine their family members, social distancing for the whole population, all public gatherings/most workplaces shut down, schools and universities close.
Suppression works! The death rate in the US peaks 3 weeks from now at a few thousand deaths, then goes down. We hit but don't exceed the number of available ventilators. The nightmarish death tolls from the rest of the study disappear.
But here's the catch: if we EVER relax suppression before a vaccine is administered to the entire population, COVID-19 comes right back and kills millions of Americans in a few months, the same as before.
After the 1st suppression period ends in July, we could probably lift restrictions for a month, followed by 2 more months of suppression, in a repeating pattern without triggering an outbreak or overwhelming the ventilator supply. Staggering breaks by city could do a bit better.
But we simply cannot EVER allow the virus to spread throughout the entire population in the way other viruses do, because it is just too deadly. If lots of people we know end up getting COVID-19, it means millions of Americans are dying. It simply can't be allowed to happen.
How quickly will a vaccine be here? Last week three separate research teams announced they had developed vaccines. Yesterday, one of them (with FDA approval) injected its vaccine into a live person, without waiting for animal testing. That's an extreme measure, but necessary.
Now, though, they have to monitor the test subject for 14 months to make sure the vaccine is safe. This part can't be rushed: if you're going to inoculate all humans, you have to make absolutely sure the vaccine itself won't kill them. It probably won't, but you have to be sure.
Assuming the vaccine is safe and effective, it will still take several months to produce enough to inoculate the global population. For this reason, the Imperial College team estimated it will be about 18 months until the vaccine is available.
During those 18 months, things are going to be very difficult and very scary. Our economy and society will be disrupted in profound ways. And if suppression actually works, it will feel like we're doing all this for nothing, because infection and death rates will remain low.
It's easy to get people to come together in common sacrifice in the middle of a war. It's very hard to get them to do so in a pandemic that looks invisible precisely because suppression methods are working. But that's exactly what we're going to have to do. /end
There are a couple of serious problems here.
First, the model these "experts" use is based on a 6.5 day generation time and an R0 of 2.4. That then results in a mean daily growth rate of exp(ln(2.4)/6.5) = 1.144x/day
The observed actual growth rate of the unconstrained virus in populations all over the world is 1.33-1.37x/day.
Using the frequently observed value of 1.355 and their 6.5 day generation time yields an R0 of 1.355^6.5 = 7.2. !!!!!!
If they find the modeling results terrifying with their parameters, what do you call it with the real parameters? Terrifying raised to the screaming with hair on fire power?
Everything that follows from their model is invalid as a result.
Second, to get from a 1.33-1.37x/day growth to a 1.144x/day growth requires doing everything China, South Korea and others did. It requires shutting down the economy.
So what they propose actually means shutting down the economy for a month or two, then easing off for a month, cycle and repeat. That is economic suicide.
Third, this plan because it fails so badly in the modeling will utterly fail to prevent the hospitals from saturating. That drives the death rate to over 10% of those hospitalized.
Fourth, they repeat the presumption that the IFR is <1%. This is unproven. Many wish it to be true. It is not proven. At the very least, assuming it to be true and basing policy on it is a gamble with both the lives of the citizenry (literally) and of the nation. If they are even a little wrong, that's all she wrote. That is insane.
Fifth, this plan assures that everyone in the nation will ultimately catch the virus at least once. So all of the vulnerable over 55 population will contract the virus, and the maximum lethality is assured.
So what we have then in sum is a plan that wrecks the economy repeatedly for more than a year, that destroys society, that kills and maims the maximum percentage of the population, and devastates the entire medical system, while also bankrupting everyone individually, every corporate entity, and the country.
Yeah, that's a plan. Well, it is if your plan is utter and complete disastrous failure that crushes your country into a fourth world wreck.
And this is the "flatten the curve" plan.
An alternate to this was the "let's throw up our hands and let the virus have its way with us" plan.
That plan would also maximize deaths and maimings. The one advantage is that it would do it in one shot. That too would bankrupt everyone and utterly destroy the healthcare systems. But, it would only do that once, rather than repeatedly over a year or two as the "flattening the curve" plan does. Arguably, that is a better choice.
Vastly better is to do as the Chinese did. Institute massive draconian controls. Quarantine everyone for two months. Test the hell out of the population. And use aggressive contact tracing. Build surge capacity instantly for hospitals. And do it all three weeks ago. Yeah, well, that isn't entirely possible anymore.
Also vastly better is to do as the South Koreans did.
Much better is to do as the Japanese and Indonesians are doing. That's not as good as China or South Korea. But compared to what the West is doing, it is genius.
For God sakes don't do what the Europeans and Americans are doing. They were and remain entirely clueless, and hell bent on killing and maiming as many people as possible, while also destroying civil society, and the entire financial basis of society.
Precisely when did idiotocracy and kakistocracy become the dominant form of Western government, and the Forest Gump's of society become the world's modeling experts?
I would also note that just as with AGW the "experts" have been woefully horribly fatally far behind the real conditions.
And ... additionally I should note that by getting the growth rate so horribly horribly wrong, combined with a near total lack of testing that the growth of the number infected will take the leaders by surprise as it did in Italy. And seemingly out of nowhere the hospitals will be in full collapse. So when the "flattening the curve" plan fails, it will fail spectacularly with huge body counts and mass graves. Welcome to a sort of replay of the US Flu of 1917-1918 (generally mislabeled as the "Spanish" Flu).
In going back and listening to the story of that last great pandemic I suppose the one heartening thing is that this bug is tame by comparison. That one clearly had an R0 far greater than measles, a generation time of about 2 days or less, and a lethality of over 20%. It makes SARS2 seem quaint and polite by comparison. But due to the stupidity of our leadership, the greater interconnectedness of the world, and just-in-time everything, this virus will do every bit as much damage. And with 7.5 billion people alive today, the death toll will no doubt exceed that of the last great pandemic of 1918.
And oh joy, "flattening the curve" will bring added pressure and time to bear for the virus to mutate into something even more terrible, and to adapt to birds so that it becomes an annual affair.
Sam