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A Third Solution

paulbuchheit.blogspot.com

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Re: A Third Solution

#111

Post by jawns »

pdonis wrote: post #27
jawns wrote: post #11

> If we were able to identify and quarantine everyone who is contagious, including those who are asymptomatic, then we could let everyone else out of lockdown and resume ordinary social and economic activity. > Even with imperfect screening, if we are able to prevent 90% of disease transmission, then the virus’s reproductive number, or R0, will drop below one and the pandemic will quickly fade. There is no risk of re…

> I'm not sure this "test and release" strategy works unless absolutely everybody gets tested simultaneously. They don't all have to get tested literally simultaneously; but the "release" part of the strategy can't start until the "test" part has covered everybody, or at least close enough to "everybody" that the difference doesn't matter. Note that that's how the strategy is stated in what you quote: if we can ident…

But contagious status is not fixed. If you test someone, they're negative, but despite sheltering in place they pick up the virus while at a necessary doctor's appointment, then their status changes. Granted, frequent follow-up tests might identify that change, but daily tests of a sufficiently large portion of the population have a number of challenges beyond just access to the tests.

Re: A Third Solution

#112

Post by newacct583 »

stonogo wrote: post #88

Not only is it completely unrealistic at scale, the specific approach in the blog post is wildly impossible at all. It requires screeners to directly manipulate saliva samples; this is dangerous in a pandemic. The assays referred to (lazily) in a Google Scholar search are almost overwhelmingly antibody assays; this does not allow the screener to differentiate between "has COVID-19" and "had COVID-19". Also, there is…

Not to quibble too much with most of your criticism, but this one seems minor and trivially solved:

> this does not allow the screener to differentiate between "has COVID-19" and "had COVID-19"

As a policy matter, this doesn't rule out the use of the test in a pandemic management protocol at all, it just changes how it needs to be administered. For example it might require that people who are antibody-positive have a standardized note confirming recovery (in Contagion, this was a cute electronic bracelet).

The critical requirement is that we detect unknown positives, and this test would do that.

Re: A Third Solution

#113

Post by epicureanideal »

stonogo wrote: post #88

Not only is it completely unrealistic at scale, the specific approach in the blog post is wildly impossible at all. It requires screeners to directly manipulate saliva samples; this is dangerous in a pandemic. The assays referred to (lazily) in a Google Scholar search are almost overwhelmingly antibody assays; this does not allow the screener to differentiate between "has COVID-19" and "had COVID-19". Also, there is…

A shopping mall could have screeners at literally every entrance, and there are sometimes dozens of entrances at a shopping mall.

Even then, traffic might be reduced, but it would be enough traffic for something like regular life to resume. Some businesses would be able to survive, even if not all.

* IDEA *

They could also do checks in the parking lot of any business. You drive up, someone comes out to start the process and marks down your license plate. After 10 minutes they return to your car and tell you your results.

This way nobody is standing in long lines possibly spreading the disease to each other. And it scales well to large numbers of people being tested simultaneously.

There would be a lag time of 10 minutes, but throughput would be nearly the same as before COVID.

Re: A Third Solution

#114

Post by aianus »

astrophysician wrote: post #44
marcell wrote: post #6

> First of all, it’s not “just the flu”. It is something much more dangerous. Catching this virus is a bit like playing a round of Russian roulette. You’ll probably be fine, but you could end up dead I think this is mischaracterizing it. People have to die eventually. One year of existence has a mortality rate of 1%. For a 75-84 year old individual it is nearly 5%. Above 85 it's 14%. [1] The coronavirus infection fat…

> Death is sad and terrible, but we don't shut down society because people die. Yea, but COVID has the potential to kill a lot of people, quickly -- are you suggesting it's a bad idea to "shut down society" to keep our hospitals functioning? I get the point that the economic cost is severe and also comes with its own share of human cost, but we're talking about saving ~1-2 million people in the US alone by doing this…

> Several trillion dollars is still worth it

$2 trillion is 10% of GDP or the losses in ~6 months of a lockdown resulting in 80% productivity (with the assumption that everything goes back to normal immediately after the shutdown, which it won't)

So it seems like a ~6 month lockdown is warranted if you crassly value saving a life from COVID at $1 million. That's not long enough for a vaccine.

Alternatively, working backwards, you need to value a life saved at $3-$4m each to make a 18-24 month lockdown worth it.

Re: A Third Solution

#115

Post by arcticbull »

macintux wrote: post #110
arcticbull wrote: post #98

> First of all, it’s not “just the flu”. It is something much more dangerous. It is for some demographics, not all. It's safer than the flu for young folks, especially the under 10's which the flu hits pretty hard. For some it's worse, especially over 70s. > Catching this virus is a bit like playing a round of Russian roulette. You’ll probably be fine, but you could end up dead. Also true of the flu. Yes, even for th…

But unlike the flu there’s significant spread from asymptotic people, so the young are walking time bombs.

That doesn't really change anything. To the extent the vulnerable are holed up inside, everyone else is welcome to get it, display mild flu-like symptoms, and develop herd immunity.

Re: A Third Solution

#116

Post by beagle3 »

astrophysician wrote: post #44
marcell wrote: post #6

> First of all, it’s not “just the flu”. It is something much more dangerous. Catching this virus is a bit like playing a round of Russian roulette. You’ll probably be fine, but you could end up dead I think this is mischaracterizing it. People have to die eventually. One year of existence has a mortality rate of 1%. For a 75-84 year old individual it is nearly 5%. Above 85 it's 14%. [1] The coronavirus infection fat…

> Death is sad and terrible, but we don't shut down society because people die. Yea, but COVID has the potential to kill a lot of people, quickly -- are you suggesting it's a bad idea to "shut down society" to keep our hospitals functioning? I get the point that the economic cost is severe and also comes with its own share of human cost, but we're talking about saving ~1-2 million people in the US alone by doing this…

> we're talking about saving ~1-2 million people in the US alone by doing this. Several trillion dollars is still worth it...

No, we're not. 88% of people on ventilators in NYC don't survive (in a predictable pattern - 97.2% over age 65 don't for example). You might remember that just a couple of weeks ago, everyone was calling for more ventilators and every company with a workshop started building one -- because it was assumed (a) they would be needed, and (b) they would be very useful; neither is considered self evident truth (or truth at all) three weeks later.

There is no vaccine yet, and no medicine yet, and either may take a year or twenty (TTBOMK, no successful vaccine for the corona family was ever made, and not for lack of trying). Unless you assume a miracle, the assumption is everyone will get it -- and so far, our ability to significantly "save" people has not been demonstrated.

The only reasonable assumption right now is that everyone will get it, and while keeping the hospital system function is important in general, it makes little difference to those who get COVID19.

A more reasonable model is that we're avoiding a 6-8 month reduction in life expectancy, at a cost of (so far) 2 months of normal life. Whether it is worth it or not is not for me or you to decide and obviously depends on your point of view -- but it is clearly not self evident one way or another.

[0] https://www.washingtonpost.com/health/2020/04/22/coronavirus...

edit: someone is systematically downvoting all my posts on this thread. Whoeveer that is, I am not advocating for or against a course of action - I'm addressing the math. It is your right to downvote without explanation, but if you think I'm wrong, I would appreciate an explanation.

Re: A Third Solution

#117

Post by epicureanideal »

pb wrote: post #38
jawns wrote: post #24

Earlier quoted context omitted.

But how realistic is daily screening on a wide scale? You're going to face major issues with compliance.

That's why I think testing at the door is the more straightforward way to start. We can reopen factories, office buildings, even shopping malls, but no one gets in without passing the screen.

Paul, I posted this is part of another comment also, but for places like shopping malls, testers could also test people while they're in the parking lot.

No lines to spread the disease, and better throughput if you're testing many cars simultaneously rather than whoever is at the front of the line. (Although I suppose many people could be tested near the front of the line too.)

Re: A Third Solution

#118

Post by newacct583 »

jawns wrote: post #11

> If we were able to identify and quarantine everyone who is contagious, including those who are asymptomatic, then we could let everyone else out of lockdown and resume ordinary social and economic activity. > Even with imperfect screening, if we are able to prevent 90% of disease transmission, then the virus’s reproductive number, or R0, will drop below one and the pandemic will quickly fade. There is no risk of re…

> I'm not sure this "test and release" strategy works unless absolutely everybody gets tested simultaneously.

This is misunderstanding exactly the text you are quoting. The goal with epidemic management is NOT to seek out and destroy every last case of the disease.

All we need to do is reduce the spread rate so the exponent in the equation goes from above one to below one. At that point, the outbreak will shrink over time on its own. Critically, new/undetected outbreaks with an R0At that point, the population is "safe". Individuals aren't, people might still get sick randomly. But this isn't a policy for individual safety per se.

Re: A Third Solution

#119

Post by jhayward »

tlb wrote: post #55
vikramkr wrote: post #41

Earlier quoted context omitted.

Compliance is tough. And my main concern would be false positives- if we are screening more people more frequently, we would have a lower expected percent of true positives, and even a small false positive rate could lead to significant overdiagnosis and disruption. The more often the test the more stringent that requirement. I dont know much about the testing method described in the article, but I wonder if it has u…

A reasonable policy is to go home when the machine at the door to your office gives a positive result. Then get a more specific PCR test, and maybe come back to work. So the cost of a false positive can be one lost day. The false positive rate of lockdowns is 100%.

> The false positive rate of lockdowns is 100%.

If that were true lockdowns would make absolutely no difference in R0. Clearly, they do make a difference.

Re: A Third Solution

#120

Post by vikramkr »

newacct583 wrote: post #112
stonogo wrote: post #88

Not only is it completely unrealistic at scale, the specific approach in the blog post is wildly impossible at all. It requires screeners to directly manipulate saliva samples; this is dangerous in a pandemic. The assays referred to (lazily) in a Google Scholar search are almost overwhelmingly antibody assays; this does not allow the screener to differentiate between "has COVID-19" and "had COVID-19". Also, there is…

Not to quibble too much with most of your criticism, but this one seems minor and trivially solved: > this does not allow the screener to differentiate between "has COVID-19" and "had COVID-19" As a policy matter, this doesn't rule out the use of the test in a pandemic management protocol at all, it just changes how it needs to be administered. For example it might require that people who are antibody-positive have a…

I also don't think this particular test is an antibody test? It seems that this test detects viral particles based on:

"The most proven and ready to scale technology is based on surface plasmon resonance. It’s able to detect even a very small number of viral particles, which is very important because we want to detect everyone who is contagious"

(6th paragraph in the "A third solution" paragraph)

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