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Re: Genuine points of uncertainty

Posted: Mon May 17, 2021 10:56 am
by shpalman
For all we know people might have been meeting indoors already. Unless they're in a pub in such a way as it's obvious from the outside, or having such a noisy crowded party that the neighbours call the authorities, we just wouldn't know.

Re: Genuine points of uncertainty

Posted: Mon May 17, 2021 11:25 am
by discovolante
shpalman wrote:
Mon May 17, 2021 10:56 am
For all we know people might have been meeting indoors already. Unless they're in a pub in such a way as it's obvious from the outside, or having such a noisy crowded party that the neighbours call the authorities, we just wouldn't know.
I am pretty confident that's the case. What proportion of the population I dunno though, I know there have been surveys of people's perceptions of lockdown compliance and it's not safe to make assumptions, I'm just getting this from speaking to people.

Re: Genuine points of uncertainty

Posted: Mon May 17, 2021 1:00 pm
by Herainestold
Grumble wrote:
Mon May 17, 2021 5:49 am
Herainestold wrote:
Mon May 17, 2021 2:08 am
Most transmission is ocurring when people are unmasked, eating, drinking, talking. So don't do it.
Pretty hard to eat or drink with a mask on.
Exactly. You are in a restaurant, eating, drinkin, jabbering at your friends. Covid spreads.

Re: Genuine points of uncertainty

Posted: Mon May 17, 2021 1:07 pm
by Herainestold
shpalman wrote:
Mon May 17, 2021 10:39 am
sTeamTraen wrote:
Mon May 17, 2021 10:29 am
Millennie Al wrote:
Mon May 17, 2021 12:18 am
If the effectiveness of masks is low enough then they end up being harmful. People will do things that they otherwise wouldn't on the grounds that they're safe because masks are being worn. This is harmless if the activity itself is harmless, but many such activities are not.
I don't think this is necessarily true. Your model basically proposes that people want to do X and will do it without further concern as soon as they consider that they have done enough to make themselves safe. That might be the case much of the time (we know that on average people drive cars at a roughly constant level of perceived risk), but in the case of Covid, at least, it seems to me that the people who are most assiduous about wearing masks are also being careful in other ways (because they don't think the mask is completely sufficient), whereas the ones who are sloppy with masks are also taking other risks.

Human behaviour is complicated, non-linear, situation-specific, and often not strictly rational. That's why psychologists are still in business.
There was enough well akshully from "experts" about masks last year.

Except I was wrong because we didn't learn enough, either in Italy or the UK, to stop the second wave being similarly deadly to the first one. Well, morons gotta morr I suppose.

My worry is that by Italy switching to criteria based on hospital occupancy to judge whether the covids are serious enough to merit control or containment measures, we'll be throwing away a couple of weeks of advance warning in a similar way to how we basically carried on as normal during the obvious exponential growth in October.
Hospitalizations, being a lagging indicator, make no sense as a trigger on the way up the infection curve. Especially after how many waves, we know that acting quickly saves lives, dithering and prevaricating causes death. It makes more sense as an unlock indicator on the way down the curve, by the time hospitalizations are declining, the infection rate is going down.

Re: Genuine points of uncertainty

Posted: Mon May 17, 2021 1:09 pm
by Herainestold
shpalman wrote:
Mon May 17, 2021 10:56 am
For all we know people might have been meeting indoors already. Unless they're in a pub in such a way as it's obvious from the outside, or having such a noisy crowded party that the neighbours call the authorities, we just wouldn't know.
This is a huge problem. Mixing of households inside where nobody can see them. I dont know how you guard against that, except keeping people from leaving their own household.

Re: Genuine points of uncertainty

Posted: Mon May 17, 2021 1:29 pm
by shpalman
Herainestold wrote:
Mon May 17, 2021 1:09 pm
shpalman wrote:
Mon May 17, 2021 10:56 am
For all we know people might have been meeting indoors already. Unless they're in a pub in such a way as it's obvious from the outside, or having such a noisy crowded party that the neighbours call the authorities, we just wouldn't know.
This is a huge problem. Mixing of households inside where nobody can see them. I dont know how you guard against that, except keeping people from leaving their own household.
My point is that if people have been doing it already then it obviously doesn't really matter.

Re: Genuine points of uncertainty

Posted: Mon May 17, 2021 1:36 pm
by Herainestold
shpalman wrote:
Mon May 17, 2021 1:29 pm
Herainestold wrote:
Mon May 17, 2021 1:09 pm
shpalman wrote:
Mon May 17, 2021 10:56 am
For all we know people might have been meeting indoors already. Unless they're in a pub in such a way as it's obvious from the outside, or having such a noisy crowded party that the neighbours call the authorities, we just wouldn't know.
This is a huge problem. Mixing of households inside where nobody can see them. I dont know how you guard against that, except keeping people from leaving their own household.
My point is that if people have been doing it already then it obviously doesn't really matter.
With a new more transmissable variant, the same activity will lead to an increase in cases.

Re: Genuine points of uncertainty

Posted: Mon May 17, 2021 11:08 pm
by sTeamTraen
discovolante wrote:
Mon May 17, 2021 10:48 am
Hm, I'm not really sure I'm looking for a counter-intuitive prediction, just a fairy standard 'if you stop people doing stuff they want to do, people (but not everyone) will often keep doing it, but where you can't see them'. But I think it's fair to say that people get used to masks etc and probably one of the biggest reasons why what I suggested might happen probably wouldn't happen is because enforcement of non-mask wearing seems to be fairly weakly enforced, as far as I can gather - I might be wrong - but it would be even more difficult to enforce outside, again as I say in places where compliance isn't more or less universal. And I'm also not sure what proportion of the public would prefer to risk meeting indoors than be forced to wear a mask outside, it might be pretty low.
I'm not aware of mask-wearing being strictly enforced here in Spain. People have just got used to it. When we see news footage from almost any other European country that involves street scenes, Mrs sTeamTraen and I just yell "Masks! Wear a f.cking mask!!!" at the TV. I have no concrete evidence, but I like to think that the reason our 3rd wave has been half (nationally) and one-tenth (locally) of what has been seen in FR/DE/NL/IT, despite our schools and some restaurants being open (and, I discovered recently, cinemas - since March!) is because people are doing such a good job with the masks.

Re: Genuine points of uncertainty

Posted: Tue May 18, 2021 7:31 am
by Woodchopper
sTeamTraen wrote:
Mon May 17, 2021 11:08 pm
discovolante wrote:
Mon May 17, 2021 10:48 am
Hm, I'm not really sure I'm looking for a counter-intuitive prediction, just a fairy standard 'if you stop people doing stuff they want to do, people (but not everyone) will often keep doing it, but where you can't see them'. But I think it's fair to say that people get used to masks etc and probably one of the biggest reasons why what I suggested might happen probably wouldn't happen is because enforcement of non-mask wearing seems to be fairly weakly enforced, as far as I can gather - I might be wrong - but it would be even more difficult to enforce outside, again as I say in places where compliance isn't more or less universal. And I'm also not sure what proportion of the public would prefer to risk meeting indoors than be forced to wear a mask outside, it might be pretty low.
I'm not aware of mask-wearing being strictly enforced here in Spain. People have just got used to it. When we see news footage from almost any other European country that involves street scenes, Mrs sTeamTraen and I just yell "Masks! Wear a f.cking mask!!!" at the TV. I have no concrete evidence, but I like to think that the reason our 3rd wave has been half (nationally) and one-tenth (locally) of what has been seen in FR/DE/NL/IT, despite our schools and some restaurants being open (and, I discovered recently, cinemas - since March!) is because people are doing such a good job with the masks.
As you point out, there are different forms of enforcement. For something like masks where everyone can see who is wearing or not, the costs of wearing are low and benefits of not wearing are marginal, laws enforced by police are a very blunt instrument that often results in resentment. Much more effective is social disapproval. Perhaps there has been much more of that in Spain than elsewhere.

Re: Genuine points of uncertainty

Posted: Tue May 18, 2021 8:11 am
by discovolante
My initial post was specifically about places where compliance is relatively low (reflecting on bolo's post about it being completely normalized where they are), where social shame is presumably less likely to be a factor.

Re: Genuine points of uncertainty

Posted: Tue May 18, 2021 9:34 am
by shpalman
There's plenty of mask wearing here in Lombardy, in fact people started wearing masks before it was mandated last year, and we still had a shocking excess mortality from the first wave and a peak of 600 cases per week per 100,000 in the second wave. Only the Province of Bergamo seemed to learn from the first wave in order to avoid a second one, or maybe all the old people already died.

Lombardy is only now descending through 70/week/100,000 but the province of Como is stuck around 100.

(If the 33,360 officially recognised covid deaths in Lombardy were scaled up to a population the size of the UK's it would correspond to about 220,000).

Re: Genuine points of uncertainty

Posted: Tue May 18, 2021 10:47 am
by Bird on a Fire
Yes, masks in the street is normal in Portugal too.

I think Chopper's point about social pressure is an important one - my vague sense from living in a bunch of places is that there's a stronger sense of "living in a society" down here, but don't ask me to quantify that ;)

Certainly if I pop across the road without a mask to take the rubbish out I get surprised looks, which has prompted me to mask up now.

Re: Genuine points of uncertainty

Posted: Tue May 18, 2021 10:57 am
by Woodchopper
discovolante wrote:
Tue May 18, 2021 8:11 am
My initial post was specifically about places where compliance is relatively low (reflecting on bolo's post about it being completely normalized where they are), where social shame is presumably less likely to be a factor.
Yes, indeed.

Re: Genuine points of uncertainty

Posted: Tue May 18, 2021 11:01 am
by headshot
Here in the West Midlands, mask wearing outdoors is almost none existent. The guidance doesn't call for it, and I haven't seen anyone wearing them other than if they're in a busy high street or transferring between indoor space.

Indoors I'd say compliance is >95%.

ANECDATA TW: Those not wearing masks always seem to be the same type: 20/30 year old males, cocky, workwear. Not someone I'd feel comfortable challenging, for fear of an aggressive response.

Re: Genuine points of uncertainty

Posted: Tue May 18, 2021 1:43 pm
by sTeamTraen
Woodchopper wrote:
Tue May 18, 2021 7:31 am
sTeamTraen wrote:
Mon May 17, 2021 11:08 pm
I'm not aware of mask-wearing being strictly enforced here in Spain. People have just got used to it. When we see news footage from almost any other European country that involves street scenes, Mrs sTeamTraen and I just yell "Masks! Wear a f.cking mask!!!" at the TV. I have no concrete evidence, but I like to think that the reason our 3rd wave has been half (nationally) and one-tenth (locally) of what has been seen in FR/DE/NL/IT, despite our schools and some restaurants being open (and, I discovered recently, cinemas - since March!) is because people are doing such a good job with the masks.
As you point out, there are different forms of enforcement. For something like masks where everyone can see who is wearing or not, the costs of wearing are low and benefits of not wearing are marginal, laws enforced by police are a very blunt instrument that often results in resentment. Much more effective is social disapproval.
I have been attempting to combine these two approaches. When Mrs sTeamTraen and I are out and about in Palma and encounter people without a mask, almost all of whom are also obviously tourists from other visual cues, I will sometimes say, "Excuse me, you might want to put a mask on. The police are just up the road handing out fines", in German (80% of our tourists right now are German). It's fun watching them scramble to find their masks, or decide if they're going to go back to their hotel to get one. :twisted:

Re: Genuine points of uncertainty

Posted: Tue May 18, 2021 4:45 pm
by shpalman
tweets on fomites versus aerosols and clips demonstrating the problem with indoor mixing.
20210518_184436.jpg
20210518_184436.jpg (71.21 KiB) Viewed 440 times

Re: Genuine points of uncertainty

Posted: Sun Jun 06, 2021 5:42 pm
by Woodchopper

Evidence for lack of transmission by close contact and surface touch in a restaurant outbreak of COVID-19

Highlights


Long-range airborne transmission in the restaurant is fully supported

Fomite and close contact routes in the Guangzhou restaurant outbreak are ruled out

Diners and staffs spent 20% of their time on close contact in the restaurant

Diners and staffs spent 90% of their time touching surfaces in the restaurant

Almost no close contact happened between diners from different tables


Abstract

Background: Coronavirus disease 2019 (COVID-19) is primarily a respiratory disease that has become a global pandemic. Close contact plays an important role in infection spread, while fomite may also be a possible transmission route. Research during the COVID-19 pandemic has identified long-range airborne transmission as one of the important transmission routes although lack solid evidence.

Methods: We examined video data related to a restaurant associated COVID-19 outbreak in Guangzhou. We observed more than 40,000 surface touches and 13,000 episodes of close contacts in the restaurant during the entire lunch duration. These data allowed us to analyse infection risk via both the fomite and close contact routes.

Results: There is no significant correlation between the infection risk via both fomite and close contact routes among those who were not family members of the index case. We can thus rule out virus transmission via fomite contact and interpersonal close contact routes in the Guangzhou restaurant outbreak. The absence of a fomite route agrees with the COVID-19 literature.

Conclusions: These results provide indirect evidence for the long-range airborne route dominating SARS-CoV-2 transmission in the restaurant. We note that the restaurant was poorly ventilated, allowing for increasing airborne SARS-CoV-2 concentration.

https://www.journalofinfection.com/arti ... 5/fulltext

Re: Genuine points of uncertainty

Posted: Mon Jul 12, 2021 12:59 pm
by shpalman
Hygiene theatre
According to the CDC, the chance of contracting Covid-19 from a single infected surface is less than 1 in 10,000. And yet we remain obsessed with fomite transmission of Covid-19, as do our elected leaders. In June, a glove-wearing Boris Johnson was filmed wiping down a plastic chair, in a worrying indication of the prime minister’s lack of understanding.
Although the CDC's stance on masks right now - that fully vaccinated people can stop wearing them - is also rather unhelpful.

Re: Genuine points of uncertainty

Posted: Mon Jul 12, 2021 2:34 pm
by Herainestold
shpalman wrote:
Mon Jul 12, 2021 12:59 pm
Hygiene theatre
According to the CDC, the chance of contracting Covid-19 from a single infected surface is less than 1 in 10,000. And yet we remain obsessed with fomite transmission of Covid-19, as do our elected leaders. In June, a glove-wearing Boris Johnson was filmed wiping down a plastic chair, in a worrying indication of the prime minister’s lack of understanding.
Although the CDC's stance on masks right now - that fully vaccinated people can stop wearing them - is also rather unhelpful.
Fully vaccinated people are likely to be asymptomatic spreaders. The numbers of new cases certainly suggest that vaccinated people are a major source of new infections. Now is not the time to ditch mask mandates. Everybody should be masked indoors and out.

Re: Genuine points of uncertainty

Posted: Mon Jul 12, 2021 3:40 pm
by bolo
shpalman wrote:
Mon Jul 12, 2021 12:59 pm
Although the CDC's stance on masks right now - that fully vaccinated people can stop wearing them - is also rather unhelpful.
It's a tradeoff. If all fully vaccinated people wore masks, that would somewhat reduce transmission. On the other hand, if the guidance said that fully vaccinated people should still wear masks, that would somewhat reduce the incentive to get vaccinated.

Re: Genuine points of uncertainty

Posted: Mon Jul 12, 2021 9:25 pm
by jimbob
Herainestold wrote:
Mon Jul 12, 2021 2:34 pm
shpalman wrote:
Mon Jul 12, 2021 12:59 pm
Hygiene theatre
According to the CDC, the chance of contracting Covid-19 from a single infected surface is less than 1 in 10,000. And yet we remain obsessed with fomite transmission of Covid-19, as do our elected leaders. In June, a glove-wearing Boris Johnson was filmed wiping down a plastic chair, in a worrying indication of the prime minister’s lack of understanding.
Although the CDC's stance on masks right now - that fully vaccinated people can stop wearing them - is also rather unhelpful.
Fully vaccinated people are likely to be asymptomatic spreaders. The numbers of new cases certainly suggest that vaccinated people are a major source of new infections. Now is not the time to ditch mask mandates. Everybody should be masked indoors and out.
Outdoors? If you're not in close proximity to someone, what would that do? What is the reduction in risk for sitting in a city park with a mask compared to without? You do have to balance benefits and risks. reducing compliance elsewhere would be a problem.

Re: Genuine points of uncertainty

Posted: Mon Jul 12, 2021 11:09 pm
by Millennie Al
Herainestold wrote:
Mon Jul 12, 2021 2:34 pm
Fully vaccinated people are likely to be asymptomatic spreaders.
Do you have a source for that? (Or, strictly speaking, what I assume you intended to say, which is that infected fully vaccinated people are likely to be asymptomatic spreaders, since the uninfected certainly are not).

Re: Genuine points of uncertainty

Posted: Tue Jul 13, 2021 12:21 am
by Herainestold
Millennie Al wrote:
Mon Jul 12, 2021 11:09 pm
Herainestold wrote:
Mon Jul 12, 2021 2:34 pm
Fully vaccinated people are likely to be asymptomatic spreaders.
Do you have a source for that? (Or, strictly speaking, what I assume you intended to say, which is that infected fully vaccinated people are likely to be asymptomatic spreaders, since the uninfected certainly are not).
Sorry, yes infected fully vaccinated people. Israeli data showed Pfizer with 64% efficacy against infection and 93% against severe disease hospitalization and death. So that leaves 30% of fully vaccinated infected people who could be spreading the infection.

Re: Genuine points of uncertainty

Posted: Tue Jul 13, 2021 7:55 am
by Chris Preston
The news reports stated that the vaccine was 64% effective against both infection and symptomatic illness for the delta variant and 93% effective against hospitalisation.

The research on the original COVID-19 showed 2 doses of vaccines was 92% effective against documented infection as shown by PCR tests and 94% effective against symptomatic infections.

The Pfizer vaccine, at least, stops detectable infection occurring. It is not the case that it increases the amount of asymptomatic infections.

Re: Genuine points of uncertainty

Posted: Tue Jul 13, 2021 1:49 pm
by jimbob
Chris Preston wrote:
Tue Jul 13, 2021 7:55 am
The news reports stated that the vaccine was 64% effective against both infection and symptomatic illness for the delta variant and 93% effective against hospitalisation.

The research on the original COVID-19 showed 2 doses of vaccines was 92% effective against documented infection as shown by PCR tests and 94% effective against symptomatic infections.

The Pfizer vaccine, at least, stops detectable infection occurring. It is not the case that it increases the amount of asymptomatic infections.
Phase plot for England. Rolling 7-day hospital admissions against rolling 7-day cases from September 2020:

Image

This is less severe - by how much it's hard to see, and the "gears" seem to be slipping as a doubling in cases isn't leading to a doubling in admissions. Presumably with vaccine protection improving over time during this wave.