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Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

science.sciencemag.org

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Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#21

Post by f38zf5vdt »

JetSetWilly wrote: post #11
raphlinus wrote: post #8

Earlier quoted context omitted.

That's a lot of interpretation from 6 cases. There's a lot of serological testing being done right now, and we'll have hard data soon, but from what I see from expert epidemiologists (disclosure: I'm not one myself), the idea that we have a vast number of completely asymptomatic cases is wishful thinking.

Ah, but if you do a sample of 1000 then even low numbers of positives are still statistically significant. The poisson distribution on just 6 might be somewhat wide but you can give a reasonable confidence interval (ie 0.3-0.9%) - and either end of that interval still suggests a lot of undetected cases at a time when there was hardly any officially. What you can't do - statistically - is say "oh there were just 6, th…

edit: removed for potentially being misleading.

Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#22

Post by chvid »

JetSetWilly wrote: post #4

This paper seems to have every imaginable scenario of which 2022 is a worst case. But, now actual data is starting to come in - such as the extremely interesting serum testing in Scotland (1) - which suggests that the infection rate is much much higher than previously supposed. The Scotland serum testing shows that around 35000 people were infected at a time when only 110 cases were known officially, and strongly sug…

There is a study in Germany done on an outbreak in Heinsberg that has a similar result.

Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#23

Post by JetSetWilly »

f38zf5vdt wrote: post #21
JetSetWilly wrote: post #11

Earlier quoted context omitted.

Ah, but if you do a sample of 1000 then even low numbers of positives are still statistically significant. The poisson distribution on just 6 might be somewhat wide but you can give a reasonable confidence interval (ie 0.3-0.9%) - and either end of that interval still suggests a lot of undetected cases at a time when there was hardly any officially. What you can't do - statistically - is say "oh there were just 6, th…

edit: removed for potentially being misleading.

Cross-reactivity is an issue in the ELISA test (the actual antibody test).

But they validated their results with a second step, the "pseudotype neutralisation assay". This test is highly specific for SARS-CoV-2 - as I understand it, they essentially introduce the virus to the hypothetically immune blood samples and then test that it is indeed neutralised by antibodies.

So, I think this Scottish serology test is pretty robust and accounts for these issues with cross-reactivity and specificity of the testing. In addition - they used a control sample from December 2019 none of which tested positive.

Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#24

Post by jdjrirkfkfk »

JetSetWilly wrote: post #11
raphlinus wrote: post #8

Earlier quoted context omitted.

That's a lot of interpretation from 6 cases. There's a lot of serological testing being done right now, and we'll have hard data soon, but from what I see from expert epidemiologists (disclosure: I'm not one myself), the idea that we have a vast number of completely asymptomatic cases is wishful thinking.

Ah, but if you do a sample of 1000 then even low numbers of positives are still statistically significant. The poisson distribution on just 6 might be somewhat wide but you can give a reasonable confidence interval (ie 0.3-0.9%) - and either end of that interval still suggests a lot of undetected cases at a time when there was hardly any officially. What you can't do - statistically - is say "oh there were just 6, th…

Doesnt poisson distribution require no correlation? Is it correct to use it for an epidemic with chains of transmission?

Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#25

Post by f38zf5vdt »

JetSetWilly wrote: post #23
f38zf5vdt wrote: post #21

Earlier quoted context omitted.

edit: removed for potentially being misleading.

Cross-reactivity is an issue in the ELISA test (the actual antibody test). But they validated their results with a second step, the "pseudotype neutralisation assay". This test is highly specific for SARS-CoV-2 - as I understand it, they essentially introduce the virus to the hypothetically immune blood samples and then test that it is indeed neutralised by antibodies. So, I think this Scottish serology test is prett…

Yeah, I read more into their assay and I'm inclined to agree with you.

Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#26

Post by llort2 »

It's very clear at this point that many of the deaths that are being reported as Covid deaths are actually in fact not. Also, the projections are so insanely off that these "scientists" should be held accountable for propagating lies and murdering the economy.

I'm curious to learn what other "science" is demonstrably false.

OPEN THE COUNTRY!

Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#28

Post by tgb »

JetSetWilly wrote: post #23
f38zf5vdt wrote: post #21

Earlier quoted context omitted.

edit: removed for potentially being misleading.

Cross-reactivity is an issue in the ELISA test (the actual antibody test). But they validated their results with a second step, the "pseudotype neutralisation assay". This test is highly specific for SARS-CoV-2 - as I understand it, they essentially introduce the virus to the hypothetically immune blood samples and then test that it is indeed neutralised by antibodies. So, I think this Scottish serology test is prett…

0 out of 100 controls and 6 out of 500 gives a very wide confidence interval. You could easily get those numbers with 1% false positives and no true positives in either group. Is your prior for false positives low enough to rule that out?

Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#29

Post by JetSetWilly »

tgb wrote: post #28
JetSetWilly wrote: post #23

Earlier quoted context omitted.

Cross-reactivity is an issue in the ELISA test (the actual antibody test). But they validated their results with a second step, the "pseudotype neutralisation assay". This test is highly specific for SARS-CoV-2 - as I understand it, they essentially introduce the virus to the hypothetically immune blood samples and then test that it is indeed neutralised by antibodies. So, I think this Scottish serology test is prett…

0 out of 100 controls and 6 out of 500 gives a very wide confidence interval. You could easily get those numbers with 1% false positives and no true positives in either group. Is your prior for false positives low enough to rule that out?

They did two independent assays so I would think the false positives rate should be far below 1% - certainly the authors seem to think so.

Secondly if they were false positives, I would expect them to be randomly distributed. Not concentrated in the affluent capital city, and not solely in the second cohort with none in the early march cohort (as you would predict if exponential growth is occurring).

Re: Projecting the transmission dynamics of SARS-CoV-2 through postpandemic period

#30

Post by cm2187 »

JetSetWilly wrote: post #4

This paper seems to have every imaginable scenario of which 2022 is a worst case. But, now actual data is starting to come in - such as the extremely interesting serum testing in Scotland (1) - which suggests that the infection rate is much much higher than previously supposed. The Scotland serum testing shows that around 35000 people were infected at a time when only 110 cases were known officially, and strongly sug…

And also a similar study in Germany with similar results [1]. The result is of course to mechanically reduce the fatality rate to a number close to that of the flu (the problem for hospitals being not so much the fatality rate than the high number of infections), and well within the 0.1-1% range that US health authorities have been advertising for a while.

Regarding models, it seems 0.15% is the new basis [2].

Even on the optimistic end of the range (0.1% fatality), with 13k deaths, that's 20% of the UK population infected, a long way from achieving herd immunity.

The other thing is that I invite people on hackernews to better control their anxiety. It is not so long ago that pointing that case fatality ratios in jurisdictions that didn't do mass testing and where there seemed to be many unreported cases with mild symptom was overestimating the fatality rate would get you treated of conspirary theorist. South Korea had been measuring a fatality ratio in that range (~0.6%) over a month ago and that was probably already an upper bound (due to not testing 100% of the population).

[1] https://mobile.twitter.com/AmeshAA/status/124944656101010637...

[2] https://mobile.twitter.com/AmeshAA/status/124902067755179622...

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