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Covid-19: The T Cell Story

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Re: Covid-19: The T Cell Story

#91

Post by tpm »

tomp wrote: post #90
chimprich wrote: post #87

Earlier quoted context omitted.

> A better explanation for the leveling off is simply that social distancing and lockdowns have reduced the spread of the virus. You are probably correct, but it still seems to be the case that the virus spread is slowing faster than expected even with relaxations of lockdown measures. I suspect the explanation is complex. It is probably a combination of factors: individual awareness in reducing social contact, north…

Why do you think "northern hemisphere summer" would have any (positive) impact? I mean, just look at Brazil, an "eternal summer" country, they're not doing that well... Except if it's the combination of heat+low humidity, there might be counterexamples to that as well though (Iran?).

People spend much more time outside and the school is off. Also the European summer is mostly not as hot as the Brazilian.

Re: Covid-19: The T Cell Story

#92

Post by jpxw »

redis_mlc wrote: post #71
ziga wrote: post #12

Earlier quoted context omitted.

Imperial College report showing mobility trends explain over 80% of observed variations in transmission: https://www.imperial.ac.uk/media/imperial-college/medicine/m...

> Imperial College report Imperial College is always wrong.

On what?

Re: Covid-19: The T Cell Story

#93

Post by GreenHeuristics »

newmana wrote: post #84
nodamage wrote: post #9

> And wherever we look, infections level off before 10%-20% of the population is infected. This is somewhat mysterious. This is not really true. Bergamo had a 58% infection rate as of last month: https://bergamo.corriere.it/notizie/cronaca/20_maggio_22/ber... Several prisons have seen infection rates in the 70-80% range: https://www.npr.org/sections/coronavirus-live-updates/2020/0... The USS Theodore Roosevelt had an…

Sweden has achieved about 15% infection rate and has showed no signs of slowing. https://www.smh.com.au/world/asia/new-beijing-outbreak-raise... https://www.worldometers.info/coronavirus/country/sweden/

No, the 14% figure is for people that self-requested testing. You can see it as an upper boundary, but it won't be the actual figure, which is likely around 8% or so.

Re: Covid-19: The T Cell Story

#94

Post by chimprich »

tomp wrote: post #90
chimprich wrote: post #87

Earlier quoted context omitted.

> A better explanation for the leveling off is simply that social distancing and lockdowns have reduced the spread of the virus. You are probably correct, but it still seems to be the case that the virus spread is slowing faster than expected even with relaxations of lockdown measures. I suspect the explanation is complex. It is probably a combination of factors: individual awareness in reducing social contact, north…

Why do you think "northern hemisphere summer" would have any (positive) impact? I mean, just look at Brazil, an "eternal summer" country, they're not doing that well... Except if it's the combination of heat+low humidity, there might be counterexamples to that as well though (Iran?).

It's a guess, but a plausible one. We know the virus is destroyed quickly by UV light, which is stronger in summer. People spend more time outside in summer, and we know transmission is reduced outside. Other respiratory viruses spread poorly in summer.

It's hard to compare with Brazil, because the stats coming out of there are poor and they're making less attempt at controlling the virus compared to almost any other country.

Re: Covid-19: The T Cell Story

#95

Post by WildParser »

phreeza wrote: post #77
WildParser wrote: post #58

Earlier quoted context omitted.

It falls down exponentially! Just look at it. If you do a bit of math you will see that f will just converge.

I think it really depends on your underlying dynamics, but I just want to point out that f'/f going to zero does really not imply that f will converge. If for example you are in a still strongly growing (but no longer exponential) regime where you can approximate the currently infected number of persons as proportional to t^2 , and there is some constant IFR, then f'(t) is also proportional to t^2. f(t) will then be…

And I still politely ask you to just look at the data. There is nothing in the data that points to "somehow" and "maybe". It is just a straight linear line in the logscale.

You may see some wobble caused by outbreaks here and there, but the mechanics of COVID-19 are always the same.

Going to zero exponentially does mean it will converge mathematically. And t^-1 won't look like the things that can be observed. There is no such thing as a constant upward trend away from the exponential. If you look carefully and do some regressions you can see some ups and downs. Changes in the behaviour of the people are able to modify the trend, but there is no constant movement away from an exponential.

You can always add an upper exponential bound that will converge below single digits per day before there is any chance that the lines cross.

Re: Covid-19: The T Cell Story

#96

Post by dalore »

tomp wrote: post #90
chimprich wrote: post #87

Earlier quoted context omitted.

> A better explanation for the leveling off is simply that social distancing and lockdowns have reduced the spread of the virus. You are probably correct, but it still seems to be the case that the virus spread is slowing faster than expected even with relaxations of lockdown measures. I suspect the explanation is complex. It is probably a combination of factors: individual awareness in reducing social contact, north…

Why do you think "northern hemisphere summer" would have any (positive) impact? I mean, just look at Brazil, an "eternal summer" country, they're not doing that well... Except if it's the combination of heat+low humidity, there might be counterexamples to that as well though (Iran?).

It's not the heat but the UV exposure and people's ability to create vitamin D from it. People in countries that have "eternal summer" tend not to go out in the sun as it's hot. Also skin pigmentation is a big factor.

Re: Covid-19: The T Cell Story

#97

Post by blendergeek »

ajsnigrutin wrote: post #82
raducu wrote: post #72

Earlier quoted context omitted.

I know hn doesn't like sarcasm, but saying that infection level off after 10-20% "naturally" after the world experienced the biggest lockdown since the spanish flu, is like saying the fire I saw on the news was extinguished because I took a pee at the same time. Nevermind resurgences post lockdown in shithole places where people don't follow distancing and don't wear masks -- like India or my belloved Romania -- sure…

> I know hn doesn't like sarcasm, but saying that infection level off after 10-20% "naturally" after the world experienced the biggest lockdown since the spanish flu, is like saying the fire I saw on the news was extinguished because I took a pee at the same time. The weird thing is, that after reopening many thing/services in many places, there were very rarely any new spikes in new cases. We've all been expecting a…

Have you checked out Florida, Arizona, or California lately?

Re: Covid-19: The T Cell Story

#98

Post by stupidcar »

acqq wrote: post #59
mlyle wrote: post #32

Earlier quoted context omitted.

"This phenomenon is called overdispersion, and it means that while on average a patient infects 2 or 3 new people, this average consists of many people infecting nobody, and then some mass spreading events infecting many more. "

> then some mass spreading events infecting many more The point is however that it is impossible that the choir selected their members based on the criteria of "members can be only these who will be easily infected with the at the moment still unknown disease." There the existence of the superspreading event to "80% of some random selection" disproves the hypothesis that "on average much less than 80% of the populati…

Just because the choir couldn't select its members on the basis of lower immunity, doesn't it mean it didn't select them (or they self-selected on) the basis of some characteristic(s) that happened to correlate with lower immunity, e.g. age, biological gender, ethnicity, socioeconomic status, etc.

The same is true of any other sub-population this is not a true random sample of the global population, like prisons, care homes, even settlements like towns and villages. If you can make any prediction about their members with greater confidence than you could with a random member of the whole population, then they are not random in the sense that matters.

Explaining how and why the characteristics of those sub-populations could correlate with greater natural immunity is certainly a challenge to those advocating for the idea of some level of latent immunity. But, likewise, substantially different outcomes in sub-populations that engaged in similar interventions is a challenge for those advocating that only interventions matter. For example, I've not heard a convincing explanation for Germany's relative success based only on the quality of its healthcare system and interventions. That isn't to deny that they played an important role, just that they may not have been the whole story.

Re: Covid-19: The T Cell Story

#99

Post by ido »

jnxx wrote: post #88
ajsnigrutin wrote: post #82

Earlier quoted context omitted.

> I know hn doesn't like sarcasm, but saying that infection level off after 10-20% "naturally" after the world experienced the biggest lockdown since the spanish flu, is like saying the fire I saw on the news was extinguished because I took a pee at the same time. The weird thing is, that after reopening many thing/services in many places, there were very rarely any new spikes in new cases. We've all been expecting a…

> The weird thing is, that after reopening many thing/services in many places, there were very rarely any new spikes in new cases. We've all been expecting a spike after every measure being removed, and it hasn't happened in most countries I think at least part of the people keep distancing to some degree, and even if that does not prevent a new spike or outbreak completely, it slows it spread. That's another critica…

Here in Germany there has been a lot of lifting of restrictions for weeks now but still everyone wears masks in shops/transit & a lot of people work from home (that didn't before). No large gatherings (like concerts or conferences) & international travel is a small fraction of what it was pre-corona.

So I can imagine there's a large effect still of even these milder (and partially voluntary) measures.

Re: Covid-19: The T Cell Story

#100

Post by rimliu »

acqq wrote: post #80
jacobush wrote: post #62

Earlier quoted context omitted.

These cold viruses circle the globe too, and just because some children had colds and transferred them to adults, does not mean that they had exactly the strain that could potentially give partial Covid19 immunity. So while I agree with your general advice about sources, I don't find your "apparently" to be apparent at all.

> while I agree with your general advice about sources, I don't find your "apparently" to be apparent at all. "Apparently" was used in the sense "I haven't seen and verified the sources myself" (i.e. the specific scientific material that supports the conclusion of an expert) but at least I took the effort to get the claim about that conclusion from a recognized expert directly." That is, I can't give you the ultimate…

You should look for the better source for your claims than some podcasts. It is already estblished that those who had COVID develop immunity for it, just not entirely clear how long lasting it is. But given its similarity to the original SARS it should last quite a long time.
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