Would a worldwide quarantine help? --moved to general discussion

[Algr]

Summary:: Covid 19: How effective would a two week worldwide lockdown be?

How effective would a two week worldwide lockdown be against Covid 19? In March when the news first hit, the US went swiftly into a hard lockdown. But things have mostly let up since then with mostly just masks, and hence lots of spread.

All summer we kept hearing about places that were almost Coronavirus free, only to have surges when the virus was reintroduced. It is the symptomless spreaders, not people who are obviously sick, who are infecting the most people, right? If we got as many people as possible to stay home for two weeks, could we push infections back to where they were in, say March? This sounds like something that could be done every 4-6 months until the vaccines are widespread.

Only police, food delivery to homes, hospitals, and electricity generation workers would be out. Would this help?

 

[phinds]

Summary:: Covid 19: How effective would a two week worldwide lockdown be?

Probably VERY effective, but a bit hard to say.

This sounds like something that could be done every 4-6 months until the vaccines are widespread.

No, it absolutely does not. So many people just won't put up with it that it would be almost useless. Why do you think America and other countries are in the mess they're currently IN (regarding the virus)?

 

[Algr]

The problem now is that the response is regionally uncoordinated and unending. At the end of the two weeks, everyone would be able to relax and visit friends and have parties for at least a while before the spreading got out of hand again. It is easier to do something hard if you know when the need ends.

Another advantage with doing it again is that since we have done this once, we will be better at it the second time around. People now have a better idea how much food and toilet paper they really need for two weeks. We know that meat supplies are not going to vanish.

 

[phinds]

Another advantage with doing it again is that since we have done this once, we will be better at it the second time around.

I don't think so. More and more people will just give up on it the more often it has to be done.

 

[Algr]

By late next year, people will be trusting the vaccines (unless a disaster happens) so we'd only need two more shutdowns. Possibly even just the one, if the one is done well.

 

[phinds]

By late next year, people will be trusting the vaccines (unless a disaster happens) so we'd only need two more shutdowns. Possibly even just the one, if the one is done well.

Well, that might be what we'd need, and it's not going to happen (world-wide, I mean). Your optimism is admirable except that it ignores the real world.

 

[jim mcnamara]

Anti-vaxxers and some politicians will make sure a smaller fraction of the population gets vaccinated than we now experience with levels of influenza vaccinations. Plus, you do realize that good vaccines create good immunity at or slightly above 90% of the patients inoculated. Not 100% goof-proof.

This thread needs to be in a non-science forum. Moved to GD.

 

[Office_Shredder]

Anti-vaxxers and some politicians will make sure a smaller fraction of the population gets vaccinated than we now experience with levels of influenza vaccinations. Plus, you do realize that good vaccines create good immunity at or slightly above 90% of the patients inoculated. Not 100% goof-proof.

They only thought they needed a 70% efficacy rate or so, so be 90% means there is lots of room for people to not take the vaccine. You only need enough people immune to drive the infection rate to below 1, which is looking pretty good right now.

 

[mfb]

Anti-vaxxers and some politicians will make sure a smaller fraction of the population gets vaccinated than we now experience with levels of influenza vaccinations. Plus, you do realize that good vaccines create good immunity at or slightly above 90% of the patients inoculated. Not 100% goof-proof.

This thread needs to be in a non-science forum. Moved to GD.

Most people realize this is worse than the flu, I expect more people to get a vaccine when they have the ability to. We now have two vaccine candidates that reduce the number of symptomatic people (bad enough to get tested) by over 90%. We are not sure how well they reduce the asymptomatic cases but it's likely that they go down a lot, too, and overall people are getting less infectious. If half of the population gets vaccinated then (a) that half is very unlikely to get harmed by the disease and (b) it's likely that we can maintain R<1 easily, i.e. new cases will go down over time without any additional measures.

This is not like measles where you need a really high fraction of vaccinated peoples because the disease spreads so extremely well.

 

[jim mcnamara]

I think you are referring to herd immunity. And if $R_0$ were as you stated we would not have our current world-wide spike. Using the US as a model, do you truly believe that we could actually innoculate 70% of the people? And that is speculative as yes or no, purely in any way. Just pointing out wishful thinking, IMO. I make no claim other than what vaccine manufacturers report. I think this ~9 minute video would help you a lot:

 

[jim mcnamara]

@mfb FWIW - the 'let it work down' concept involves ethically unacceptable deaths when a vaccine is available.

 

[mfb]

I think you are referring to herd immunity.

From vaccines, yes.

And if R were as you stated we would not have our current world-wide spike.

R, not R₀. The actual reproduction, rate, not the reproduction rate if no one is immune. Vaccinate people and R goes down.

Most likely vaccinating 50% would be more than sufficient, but I think 70% is not impossible either.

@mfb FWIW - the 'let it work down' concept involves ethically unacceptable deaths when a vaccine is available.

Who suggested that?

I think this ~9 minute video would help you a lot

In which way?

 

[russ_watters]

How effective would a two week worldwide lockdown be against Covid 19?

Only police, food delivery to homes, hospitals, and electricity generation workers would be out.

What about fire fighters, should we let them out too? The water company? How about Pfizer employees?

Would this help?

Sure. But since we're fantasizing, maybe we can just start with my 75 year old parents discontinuing their weekly 3-table bridge game? If you have any suggestions on how to make that happen, I'm totally open to them.

But things have mostly let up since then with mostly just masks, and hence lots of spread.

Masks are 97% effective, therefore the current situation can't be real.

 

[russ_watters]

I think you are referring to herd immunity. And if $R_0$ were as you stated we would not have our current world-wide spike. Using the US as a model, do you truly believe that we could actually innoculate 70% of the people?

Should we care? Healthcare workers and old people in nursing homes will be forced to inoculate. In the first few months, the vaccine won't even be available to anyone else. Then after that, why does it even matter if everyone else does/doesn't?

 

[Rive]

How effective would a two week worldwide lockdown be against Covid 19?

Likely, it would help but would not be enough. During a 'lockdown' the virus is still spreading within families and with just two weeks there is no safe buffer, so it will be still in progress: at least, for many family.

The main problem with (big) lockdowns is that it's taken as a regular mean of handling this pandemic. It is no way 'regular'. It's a nuke. By using a nuke you might mitigate a problem but:
- it actually means you have already lost
- you have to deal with the bad aftermath/aftertaste
- it has awful high collateral damage

It's better to look for countries with success and copy them instead. At least, you might get the right idea what to do after the nuke.

 

[mcastillo356]

Here in the Basque Country and in Spain we are ready for another lockdown. A recent opinion poll published at "El Pais" yesterday declares it. The 73% thinks it's more important health than economy.
https://elpais.com/sociedad/2020-11...un-segundo-confinamiento-si-es-necesario.html.
The headline states: "the majority of spanish people is in support of a second confinement if it is necessary"
Greetings!

 

[mfb]

The main problem with (big) lockdowns is that it's taken as a regular mean of handling this pandemic. It is no way 'regular'. It's a nuke. By using a nuke you might mitigate a problem but:
- it actually means you have already lost
- you have to deal with the bad aftermath/aftertaste
- it has awful high collateral damage

It's better to look for countries with success and copy them instead.

Countries with low case counts:
- a couple of small island countries in Oceania that shut their borders completely. Works for them, impractical for most other countries.
- Taiwan. Largely closed the border plus quarantine for arrivals, high rate of mask wearing as early as January, great contact tracing, limits on gatherings but no lockdown
- New Zealand. Largely closed the border plus quarantine for arrivals, implemented lockdowns to curb the local transmission.
- China. Very strict lockdowns plus other restrictions that democracies will not copy.
- Vietnam. Largely closed the borders plus quarantine for arrivals, closed schools, restaurants and many other non-essential businesses, restricted outdoor activities, strict lockdowns in some places
- South Korea. Excellent contact tracing, large test programs, high rate of mask wearing. Quarantine for arrivals, several types of businesses and education facilities were closed for a while
- Japan. Largely closed the borders, has quarantine for arrivals now. Closed schools, but apart from that largely issues recommendations. I see the success here largely coming from the population - high rate of mask wearing, high compliance with the recommendations. They are still at over 1000 new cases per day, they didn't beat the outbreak.

So, what do we copy? If we take countries without lockdown this list shrinks to the islands in Oceania, Taiwan, South Korea and Japan. All these countries are islands or their only land border is heavily fortified. That's geography you cannot copy. All of them closed their borders to most foreigners and required quarantine, which is easy if you are on islands.
With the exception of Japan all their strategies rely on avoiding community spread completely to avoid stricter measures. That's not a viable strategy in most places now.

What do we copy?

In the first few months, the vaccine won't even be available to anyone else. Then after that, why does it even matter if everyone else does/doesn't?

I strongly prefer not getting the disease over getting the disease. Do you have a different preference?

Masks are 97% effective, therefore the current situation can't be real.

What does that number mean and where does it come from?

 

[mcastillo356]

What do we copy?I strongly prefer not getting the disease over getting the disease. Do you have a different preference?What does that number mean and where does it come from?

https://www.nature.com/articles/d41586-020-02801-8
"They filter 95% of airborne particles", says the article.

What do we copy?

Nothing. USA is another country. The fact is that the disease has made us (the population) become "sanitary agents": we are part of the solution. My attitude is: mask, wash my hands, distance...
Greetings from the Basque Country!

 

[Rive]

That's geography you cannot copy.

Quarantine at arrivals is do happening right now in the middle of Europe, without any 'fortified borders'.
The same for most of the mentioned measures. There are examples for almost every part of the list.

The real difference is not about 'can't be done', since these are being done. The real difference is, that 'they' do this when there is just threat and not only when there is already a serious situation with hospitals full.

 

[russ_watters]

I strongly prefer not getting the disease over getting the disease. Do you have a different preference?

No, I don't. You missed my point, and the actual premise I was responding to. The issue was about whether enough people would choose to be vaccinated, irrespective of the required threshold. My point was that personal choice and herd immunity threshold doesn't matter much, especially if the vaccine is very effective. I don't want COVID, so I'll get vaccinated (assuming it is proven safe and effective). If someone else doesn't care and chooses not to get vaccinated, then I don't care if they get COVID. I'll be satisfied knowing that the most at-risk groups, and people who care, are protected.

Or, put another way, and this time considering the threshold: if the threshold is low enough, the virus will already be basically gone by the time anti-vaxxers get to execute their choice.

What does that number mean and where does it come from?

It's a joke based on a viral facebook graphic, in response to a poorly thought-out OP.

 

[russ_watters]

Quarantine at arrivals is do happening right now in the middle of Europe, without any 'fortified borders'.
The same for most of the mentioned measures. There are examples for almost every part of the list.

The real difference is not about 'can't be done', since these are being done. The real difference is, that 'they' do this when there is just threat and not only when there is already a serious situation with hospitals full.

No, it's not a political coincidence that the best happen to be island nations. The isolation matters a lot for how many people are entering, and it also impacts "when". New York City was hit first and worst in the USA for exactly that (opposite side of the coin) reason.

 

[mfb]

https://www.nature.com/articles/d41586-020-02801-8
"They filter 95% of airborne particles", says the article.

Not the same number, only applies to a very uncommon type of mask, and no transfer to infection risks.

Quarantine at arrivals is do happening right now in the middle of Europe, without any 'fortified borders'.

It's poorly controlled (or not controlled at all) and it doesn't apply to land borders. As russ already replied: It's not coincidence that this list is dominated by islands.

My point was that personal choice and herd immunity threshold doesn't matter much, especially if the vaccine is very effective.

For most people, yes - we are lucky with the ~95% efficacy. Not everyone can get the vaccine, however. Herd immunity will still be relevant for those who cannot.

 

[russ_watters]

For most people, yes - we are lucky with the ~95% efficacy. Not everyone can get the vaccine, however. Herd immunity will still be relevant for those who cannot.

You're changing the subject again. Jim was concerned about anti-vaxxers affecting herd immunity. If the vaccine supply is constrained, anti-vaxxers won't matter because they won't have an opportunity to decline the vaccine.

[Edit] For Pfizer, Google tells me it will have 50 million doses available by the end of the year. That's not a lot. But it is building up the shipping capability of having hundreds of millions in distribution simultaneously.

 

[Evo]

Most people realize this is worse than the flu, I expect more people to get a vaccine when they have the ability to. We now have two vaccine candidates that reduce the number of symptomatic people (bad enough to get tested) by over 90%. We are not sure how well they reduce the asymptomatic cases but it's likely that they go down a lot, too, and overall people are getting less infectious. If half of the population gets vaccinated then (a) that half is very unlikely to get harmed by the disease and (b) it's likely that we can maintain R<1 easily, i.e. new cases will go down over time without any additional measures.

This is not like measles where you need a really high fraction of vaccinated peoples because the disease spreads so extremely well.

I was amazed that when I started questioning people if they were looking forward to having a vaccine, not ONE person said they were willing to get it until other people had been vaccinated for at least a year or longer because they are afraid it was rushed through too fast to know what the side effects could be. People just don't have trust in it.

 

[Filip Larsen]

Masks are 97% effective

For what its worth, a danish study found only weak reduction in infection rates for people wearing masks. While this may be open for a lot of questions or interpretations it seems clear that 95% particulate filtering does not translate to a 95% reduction in infection rate as people in general may have hoped for (I haven't followed the discussion here so I do not know if anyone in this thread is implying that or not - I am merely reporting on the trial).

https://www.acpjournals.org/doi/10.7326/M20-6817

Background:
Observational evidence suggests that mask wearing mitigates transmission of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). It is uncertain if this observed association arises through protection of uninfected wearers (protective effect), via reduced transmission from infected mask wearers (source control), or both.
Objective:
To assess whether recommending surgical mask use outside the home reduces wearers' risk for SARS-CoV-2 infection in a setting where masks were uncommon and not among recommended public health measures.

[...]

Conclusion:
The recommendation to wear surgical masks to supplement other public health measures did not reduce the SARS-CoV-2 infection rate among wearers by more than 50% in a community with modest infection rates, some degree of social distancing, and uncommon general mask use. The data were compatible with lesser degrees of self-protection.

 

[Evo]

For what its worth, a danish study found only weak reduction in infection rates for people wearing masks. While this may be open for a lot of questions or interpretations it seems clear that 95% particulate filtering does not translate to a 95% reduction in infection rate as people in general may have hoped for (I haven't followed the discussion here so I do not know if anyone in this thread is implying that or not - I am merely reporting on the trial).

https://www.acpjournals.org/doi/10.7326/M20-6817

I have to say that "wearing masks" differs widely. I have seen too many people wearing masks that have "vents" those circular cutouts in the masks, they have a little "cover" over them that make the mask useless. Also, people wearing thin masks and/or with the wrong materials. All types of masks are not acceptable. Also people wearing the masks wrong, like under the nose, or are not flat against the face (some I have purchased buckle up on each side near the ear), I'm thinking this may be due to my having a small face, but I can't wear a tiny child's mask. I have yet to find a mask (other than an N95 mask) that doesn't have large gaps. My youngest daughter wears N95 masks due to her condition, it's dangerous for her to leave home. If everyone wore N95 masks *correctly*, I am sure there would be a large reduction in cases.

Masks with exhalation valves or vents

CDC does not recommend using masks with exhalation valves or vents because this type of mask may not prevent you from spreading COVID-19 to others. The hole in the material may allow your respiratory droplets to escape and reach others. Research on the effectiveness of these types of masks is ongoing.

https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html#:~:text=CDC does not recommend using,types of masks is ongoing.

 

[Filip Larsen]

If everyone wore N95 masks *correctly*, I am sure there would be a large reduction in cases.

One of the researchers did comment on TV along the same lines, namely that his personal expectation is that wearing masks correctly will have a measurable effect larger than what they measured in the trial and also that wearing mask (even if done incorrectly) do not seem to make the risk of infection greater. My take on this trial is that it shows what effect you can expect on a cooperating population informed about how to use a mask correctly but untrained in doing so at a time where almost no one else would be wearing masks, and in that sense the numbers are interesting to know for health authorities.

In addition to wearing a mask correctly before it can be expected to reduce risk of getting infection, there is also the anecdotal indications that wearing masks make people "feel safer" and thus they are more likely to put themselves in a situation they would refrain from if not wearing a mask. This was actually the main worry mentioned by the danish health authorities in spring given as reason why they (at the time) did not recommend masks for the general public (special groups were recommended to wear masks to protect themselves). Notice the trial was unblinded (participants obviously knew if they were given a mask or not) so it would indeed be expected that the measured effectiveness would include reduction of any such behavioral effects. It would have been interesting if they had been able to also make a blinded trial where all participants are issued identical looking masks with half of them filtering only, say, 5% of Corona sized particulates, but I guess they concluded the unblinded protocol was better at answering the concerns health authorities had about negative effects due to behavioral changes.

 

[OmCheeto]

One of the researchers did comment on TV along the same lines, namely that his personal expectation is that wearing masks correctly will have a measurable effect larger than what they measured in the trial and also that wearing mask (even if done incorrectly) do not seem to make the risk of infection greater.
...

One of the interesting things about that study is:

​

...study participants' exposure was overwhelmingly to persons not wearing masks.

​

Which is good to know. Though I already avoid mask-less people like the plague.

 

[mfb]

You're changing the subject again. Jim was concerned about anti-vaxxers affecting herd immunity. If the vaccine supply is constrained, anti-vaxxers won't matter because they won't have an opportunity to decline the vaccine.

No, the subject was always the same, the time where more vaccines are available:

In the first few months, the vaccine won't even be available to anyone else. Then after that, why does it even matter if everyone else does/doesn't?

It matters for many people how many of the population we can vaccinate once supply isn't the limit any more. If that fraction is too low then personal choice matters, too.

For what its worth, a danish study found only weak reduction in infection rates for people wearing masks.

That's consistent with the general approach that the other direction - the mask prevents you from infecting others - is more important. But with their huge uncertainties we can't really tell much.

 

[Algr]

we are part of the solution. My attitude is: mask, wash my hands, distance...

This is the solution we have now, and it it yielding the results we have now. I hope we all agree that the current situation and infection rates are unacceptable, and that more needs to be done.

I was amazed that when I started questioning people if they were looking forward to having a vaccine, not ONE person said they were willing to get it until other people had been vaccinated for at least a year or longer because they are afraid it was rushed through too fast to know what the side effects could be. People just don't have trust in it.

There are two DIFFERENT anti-vaccination issues going on. The movement that has been going on for years is not going to change, but fortunately only affects a small number of people.

 

[Algr]

When they say that a vaccine is "90% effective" what is that relative to? If you had a disease that only 50% of the population were vulnerable to, and everyone got the vaccine, would that make 90% of the people immune? Or 95% of the people immune?

 

[OmCheeto]

When they say that a vaccine is "90% effective" what is that relative to? If you had a disease that only 50% of the population were vulnerable to, and everyone got the vaccine, would that make 90% of the people immune? Or 95% of the people immune?

It would appear that they don't overthink such things.

https://www.pfizer.com/news/press-r...ntech-conclude-phase-3-study-covid-19-vaccine

43000 participants​

170 total cases​

162 cases in the placebo group​

8 cases in the vaccine group​

(162 - 8) / 162 * 100% = 95.1%​

https://www.nih.gov/news-events/new...s-clinical-trial-nih-moderna-covid-19-vaccine

>30000 participants​

95 total cases​

90 cases in the placebo group​

5 cases in the vaccine group​

​

(90 - 5) / 90 * 100% = 94.4%​

​

https://www.cdc.gov/csels/dsepd/ss1978/lesson3/section6.html

Vaccine efficacy or vaccine effectiveness​

 

[Algr]

Okay, thanks.

I was thinking of the notorious "lie detector" theoretical where a "90% accurate" lie detector ends up producing more false positives then actual positives. But I'm not sure if that applies here or not.

 

[OmCheeto]

Okay, thanks.

I was thinking of the notorious "lie detector" theoretical where a "90% accurate" lie detector ends up producing more false positives then actual positives. But I'm not sure if that applies here or not.

Ha! Please note that I've changed my post, as, while looking at the equation, although the answer came out fairly correct, it didn't strike me as making much sense.