Wednesday assorted links

1. How much do you need in the way of masks to stop an epidemic?

2. Robot dog herds sheep on a New Zealand farm.

3. Community labs and DIY biology (New Yorker, interesting piece).

4. John Cochrane talk on reopening.

5. Are airplanes actually pretty safe for Covid-19 risk?  (Not endorsing this piece or offering it up as advice, I do not myself know one way or the other.  Any opinions here?)

6. “More generally, the entire Yemeni monetary system has split on the basis of banknote age.”  The older notes of course no longer can be increased in supply and thus, if priced separately, are more stable in value.

7. Sweden is not getting to herd immunity very quickly.  This also seems to imply Swedish policy does not matter very much.

8. On the clustering of coronaviruses, recommended, important.  And more here.

9. How Hong Kong avoided nursing home deaths.


reckon transferring known infected patients into non infected nursing homes will turn out to be the 2nd bigliest avoidable pandemic mistake
made by the elites

Elites? You mean the hospitals. Elites don't transfer patients, hospitals do.

Wow, Ray, you have outdone even yourself for insipidness. No nursing home would even consider taking a patient like that without it being a state mandate.

It was not only massacring vulnerable nursing home inmates.

"Cuomo made three breathtakingly bad moves in March that in retrospect amounted to catastrophe. First, Cuomo failed to call for, and even actively discouraged, informal social-distancing measures in early March. Next was the delay in mid-March in ordering formal closures when the virus started rampaging through his state. Third was his March 25 edict to long-term care facilities that they must accept infected patients, which caused a mass deadly outbreak among helpless, trapped, elderly New Yorkers. Only in the last few days have some corners of the media begun to call attention to just how badly Cuomo has failed us.”

Cuomo's the best! See CNN, MSNBC, et al.

Morituri Te Salutant

How California VA Nursing Homes avoided deaths
Overall, California is about average terribleness, with at least1/3 of all corona deaths in nursing homes. But not the Calif VA.

It is hard to earn a badge of honor without multiple avoidable pandemic mistakes made by those in charge.

#7: that's as of early April FWIW

In any case, the fact that the numbers of cases and deaths are declining everywhere in the world around the same time (and within the US around the same time) despite major variations in shutowns, reopening, mask usage, etc. is outstanding news. The stock market picked up on this a long time ago but the data is starting to confirm.

See, e.g., Danish CDC admitting it does not know why infections aren't increasing after reopening 4 weeks ago:

My money is on seasonality being a major factor (other coronaviruses simply disappear between May and November). Hopefully we use the quiet summer to continue to grow testing capacity, setup contact tracing, and make a few billion masks before the winter.

yes . This Roxhed (KTH) and Olof Beck (Karolinska Institutet) study found 10% in Stockholm had antibodies. This was a mailing study where blood was collected before Easter ( April12)
It says:
The mailings were evenly distributed to men and women, chosen at random, and ranging in age between 20 and 74, from a population of 1.22 million people in 717,850 households.

Are cases actually declining everywhere? Or is it the gotcha of logarithmic charts again ..

If anyone has a good (non-log) chart of US and state hospitalizations per day or week, that would be great.

I second this....

Here's a pretty good chart for Florida. Hospitalizations look pretty flat for the last six weeks. That's not as bad as an increase, but it's not really showing a great fall, so far.

US hospitalizations by week:

That is good news. I'll have to bookmark that.

Indeed, an excellent bookmark.


Less than 20,000 total hospitalizations ?

The disclaimer says it represents ~10% of the US population, ~32 million people. If it's representative ..

COVID Tracking Project has current hospitalized for some but not all states here:

Click "US Daily 4pm ET" tab. Hopitalizations peaked at around 60,000 on 4/15 and have been declining since.

You can see the dramatic drop in NYC here: [scroll down to Daily Counts and click Hospitalizations]

The NYC page also shows that deaths in NYC peaked on April 7, so grow in new cases likely peaked 2-3 weeks before that.

You can also watch Cuomo's press conference. # hospitalized in NY state peaked at under 20,000 and is now down around 5,000.

FWIW? This is worth a lot. The implied death ratio, computed with yesterday May 19th, dead in Sweaden (~3800) with the estimated infection of early April (~6% according to the tweeter tweet) and Sweden's population of (10M) is about 0.65% which is higher that other similar estimates with surveys (0.15-0.4%). But if you count the dead by end of April (~2500 after upper reestimate), you get an estimated rate of about 0.4%, more in line with the other ones.

So to conclude, as expected by anyone with a brain, Sweden has a similar death rate with other rich countries or regions with similar demographics,
and has the expected infection rate, better than Danemark or Norwegian, worst than France and Italy.

But saying that Swedish's policy does not matter very much is for robots. It matter a lot to me to have the right to walk outside of my house, go to the countryside or the mountain, meet a friend, answer to my students face to face, and drink a glass of wine in a bar.

Did you scroll back and read the whole thread?

What thread are you talking about? The post of Oleg posted at 1:35pm. Obviously I didn't read when I posted my post at, exactly, 1:35pm.
We agree. He has a brain.

Or are you talking about your post "Are cases actually declining everywhere?" in this thread? I have read it, and I see no reason why you posted it in a thread about Sweden rather that as an independent new comment. Or are you talking of something else? Or perhaps you are confusing me with one of your friend: I am Joël of the Joëls, from Tusla, Oklahoma.

I just mean that Tyler linked to the last tweet in a tweet-thread, and I don't read the whole tweet-thread as that optimistic.

WHO reports most coronavirus cases in a day as cases approach five million. "The global health body said 106,000 new cases of infections of the novel coronavirus had been recorded in the past 24 hours, the most in a single day since the outbreak began."

That's from a Reuters article that was published today. Where are you hearing that "cases are declining everywhere in the world"?

Neither Brazil nor Russia are experiencing a decline, and the U.S. is not exactly declining either.

Manaus is an example where seasonality is not relevant - it is next to the equator, and has a tropical climate with minimal annual variation in heat or humidity.

I guess the lying comes easy to some people. The US is experiencing declining cases, and rapidly at that. There are basically less than half as many cases as there were just a month ago. Actual new cases have declined by around 30% in the last month while actual tests run have doubled in the same time frame.

In the case of Russia and Brazil, their actual new cases are still following the same curve as the actual testing numbers, so the call can't be made either way on whether they are experiencing an actual increase in infections, or just an increase in infections confirmed by testing.

> There are basically less than half as many cases as there were just a month ago.

Do you mean half as many daily cases?

From worldometers, U.S. daily new cases -
April 19 - 26,311
May 19 - 20, 289 (latest date)

Obviously, one can cherry pick peaks and lows, or more realistically, the reporting is uneven, but the general term for what has been going in the U.S. is plateau. Or to be generous, a very slow decline from the peak.

And the only way to claim there is less than half as many cases is to look at the absolute peak of 38,958 on April 24 and the absolute lowest number since then of 18,196 on May 11. Since that reported low, the number has varied between 22,802 on May 12 and 22,630 on May 18.

There is not much evidence of any particular decline in the U.S. compared to a country like Italy, where there is no question that new cases have been undeniably declining since late April.

Looking just at raw new case numbers is problematic since they are highly influence by the number of tests administered. And of course daily numbers are subject to some obvious cyclicality of reporting so a moving average is better if you are looking at case numbers.

But it seems clear most relevant numbers are declining in the US. From CDC:
"Nationally, levels of influenza-like illness (ILI) and COVID-19-like illness (CLI) and the percentage of specimens testing positive for SARS-CoV-2, the virus that causes COVID-19, continue to decline. Mortality attributed to COVID-19 also decreased compared to last week but remains elevated above baseline and may increase as additional death certificates are counted."

"The national percentage of respiratory specimens testing positive for SARS-CoV-2 at public health, clinical and commercial laboratories decreased from week 18 to week 19. Percentages by type of laboratory:

Public health laboratories – decreased from 13.1% during week 18 to 11.8% during week 19;
Clinical laboratories – decreased from 8.4% during week 18 to 6.9% during week 19;
Commercial laboratories – decreased from 13.0% during week 18 to 10.2% during week 19."

Hospitalizations have been declining for a several weeks now and are significantly down from their peak:

And even raw daily new case counts show a clear downward trend even given the issues with those:

Have you been following the hospitalization link for long? I wonder if there are revisions on recent weeks ..

Our World in Data has the peak 7-day rolling average at 31k and today's 7-day rolling average at 22,600.

@ Brian. It's not surprising. The US is a big country and the infection is not heterogeneous. Cases have sharply declined in New York but have increased elsewhere in the US.
It had the same pattern in the world , increasing cases in China In January but declining in February- March meanwhile increasing in Europe in March and so on.

The U.S. is declining in the increase of Covid-19 deaths a day.

Apr 8 to Apr 14: 11%
Apr 15 to Apr 21: 7%
Apr 22 to Apr 28: 4%
Apr 29 to May 5: 3%
May 6 to May 12: 2%
May 13 to May 19: 2%

About 250 years ago, Frederick (II) the Great said "He who defends everywhere defends nowhere."

Now (1:41PM), Worldometer shows 17,249 US critical cases. That's 0.005% of Americans.

They're micromanaging healthy people's lives but not isolating/protecting aged, chronically-ill people.

deaths lag so run that table in 8 weeks and look where May 13 - 19 might be.

Note, the lag is more about reporting.

8. I miss blogs. Twitter threads are so inefficient.

#1 is a cool paper.

I’d love to see one that includes heterogeneity in the model. Hopefully someone is doing it now

Yeah. Combine 1. with 8.

> My money is on seasonality being a major factor

This increasingly is looking to be true. Last week revealed several glowing articles on Australia's results, but they ignore the total cluster-eff next door to AUS in Indonesia where basically nothing was done early. And Indonesia has the same # of deaths per million as Australia. Ditto with South Africa.

And the south of the US just hasn't suffered much in any of this, generally exhibiting per-capita death rates that are half that of Germany.

China has a lot of workers in Africa (mining minerals for batteries, solar panels, semiconductors) and thus Africa was likely seeded to the same extent Italy was after Lunar New Year. And their numbers are nothing.

Finally, has anyone seen data suggesting a % of people in a population that cannot catch covid even if drenched in the virus? Those with built-in immunity were known to exist for everything from the plague to HIV in varying degrees. But perhaps 50% of the population isn't bothered by this at all, and what seems like seasonable burn-out in the norther hemisphere is actually the last gasp as the virus has effectively run its course and doesn't have any more targets to infect in places like NYC.

Countries in the southern hemisphere are entering the fall/winter portion of their seasons.

And the southern city of New Orleans and its surrounding state have been heavily impacted by covid19

Yes, but New Orleans held mardi-gras in 3rd week of February, and there was a huge number of NYers and partiers from around the the world that flew in and seeded things. It was epic stupidity, committed a time when large US companies were pulling out of shows (see Mobile World Congress) all around the world because they didn't want to expose their employees. Apple, Microsoft, Google all just walked in multi-million $ booth investments and lost their deposits on hotel rooms for a hundred employees, etc, so avoid having to congregate that same week. But not the mayor of New Orleans! She showed the virus who was boss! And then blamed Trump and claimed nobody ever told her.

I'm not saying it's 100% weather. But I'm saying there are plenty of places that did a lot more than Australia a lot sooner and were slaughtered. And plenty of places that did a lot less than Australia a lot later and were spared. And weather is a very strong component.

New Orleans in winter, while mild compared to the rest of the US, is not exactly hot. (Admittedly, it is perpetually humid there.)

Mardi Gras occurred during a cold snap:

"Temperatures should begin to drop as a cold front settles into the area. Highs will be near 65 degrees with a low Tuesday night around 44 degrees. "

The weather is clearly just one factor affecting transmission out of many. If it was the main factor we'd see much less spread in Brazil, Dominican Republic, Paraguay, Mexico, etc.

Huh? that was multiple factors. New Orlean's Mardi Gras is a large celebration with people from all over the world, where the streets are packed, with much drinking and socializing and the temperatures were fairly low.

a) cool temperatures
b) international travel nexus
c) close quarters (people literally touching strangers, throwing beads to each other)
d) socialization, people sharing drinks, sharing gifts, etc

The fact that New Orleans wasn't worse than NYC despite those factors indicates some other factor is very factor. That may well be warm temperatures, as within a few weeks New Orleans had warmed up considerably.

Sorry, that should have been a response to Phinton who said weather is a very strong component.

Finally, has anyone seen data suggesting a % of people in a population that cannot catch covid even if drenched in the virus?

I think this is probably the biggest mistake made in the early models- the assumption that the virus was so novel that over 50% of the population could ever be infected. The data to date strongly suggests that the susceptibility to the virus is far less than 50% (more like 20-30%) of the population, at least at the levels of exposure that would have prevailed prior to the population changing their behavior in significant ways. With the changes in behavior (mask wearing, handwashing, keeping distance, not talking to people face to face, etc.), the susceptibility might well be under 10% at this point.

It will interesting to see the anti-body data for the different boroughs New York City, and the counties in New Jersey. You will probably be able to estimate the actual susceptibility to the virus of the general population.

In short, I think to reach herd immunity, you actually need far less people actually catching and recovering from the virus than is generally believed- all you need is a large fraction of the population that was susceptible to it.

I can't prove it but I have always thought that there are some people ( particularly children) that basically don't catch the virus. They fight it without antibodies just with the innate response + T cell mediated immunity. The virus doesn't take hold and is cleared quickly. They're the briefly infected/ never symptomatic. Children have also less ACE2 receptors.
These people are the hardly susceptible, hardly infectious. That's why I think when the (past ) infected reach 20% then the effectively immune reach 35 to 40% due to the background asymptomatic not susceptible of maybe 15% to 20%.
with a background immunity of 40% , you can afford an R of 1.6 and still see declining cases.

It's important to note here the distinction between SARS-CoV-2 (the virus itself) and COVID-19 (the disease the virus causes). Testing positive for the presence of the virus in your body (distinct in itself from an antibody test) doesn't mean you have the disease, just as a person who tests positive for HIV doesn't automatically have AIDS. Indeed, this situation is in effect an asymptomatic "case". It's getting increasingly hard to apply Hanlon's razor to the fact that the media and their scientific experts have not tried harder to explain this distinction as well as their casual conflation of them.

Well if you test positive, even if asymptomatic, you could shed live virus. I think there are some people who don’t even test positive or very briefly.
The hallmark of severe Covid-19 cases is an impaired IFN-I response. These are proteins triggered by recognition of virus epitopes by extracellular or intracellular receptors ( no antibodies involved)
The virus evades this innate sensing in varying degree suppressing the response and the expression of IFN stimulated genes (ISG).
For some people, perhaps with a greater number of these receptors, the virus can’t fool them all and they clear the virus quickly. Some of them may have less ACE2 receptors, so the virus infects less cells anyway.
This is just a conjecture some background here:

Not sure about this. See, for example, this:

At one choir practice, one infectious person managed to pass the disease on to 45 others, out of 60 participants. That's 75%. We can speculate that the remaining 25% were naturally immune, but perhaps they were just lucky. At the very least, it seems that 75% of a population is susceptible, if not more. No reason to assume that the individuals involved in the rehearsal were outliers of any kind.

What’s the median age for church choirs?

It doesn't look like infection (as contrasted with fatal infection), differs all that much across age categories. Young people - except the very young - seem to get the disease as much as anyone else. They are just much more mild cases for the most part.

There is a difference in infect-ability and transmissibility for children Reports from Spain of children being much less infected, of Australia 's schools where a few infected schoolchildren where found not to infect anyone , etc..

True , choir practices are very infectious. There was another choir story in Amsterdam where 100/132 got infected but the participants skewed old. I think the naturally immune are found in the very young and young.
No I am not sure if it. . I just have read some evidence that points that way. The first one was that in Wuhan, they found it hard to find children testing positive.
It also explains why cases are declining in places like Sweden or NYC. Herd immunity is reached sooner than expected.

are you still seriously asserting/fraughting that sweden reached herd immunity a month ago?

no, I have never said a month ago, and not Sweden but Stockholm. I think Stockholm most likely has in early May and that's why they peaked on April 24.

If we're doing medieval philosophy meets US politics themed names, I'd like to nominate "Great Chain of Biden"?

are beginning to bet that early 20th century philosopher
c.p.'s razor has been banned from the intellectual milleau

New York did an anti-body study that was released a couple of weeks ago (or a week or 5 months... I don't know... time has stopped...wasn't that some proposal that Tyler signal boosted a couple times... anyway) that suggested something like 14% of the population of New York and around 20% of NYC had antibodies.

... time has stopped...


SWMBO & I are both mid 60ish boomers. That is the best description of how we are experiencing the current unpleasantness.

Seeing as I’m a geezer with one foot in the grave I am going to shamelessly steal that description without giving you even a tiny bit of credit.

Beyond “I saw this on a blog...”

Thanks muchly!!

There was a report I saw within the past 2 or 3 days (but don't have the link and might even have been here on MR) that basically noted testing showed antibodies in people that had never been exposed to the virus -- the sampling came from 2015 to 2018.

If the antibodies do provide some immunity to reinfection and some earlier virus is similar enough to trigger the same type of immune response there may well be "naturally" immune people walking around that will never catch the virus.

People on the USS Roosevelt tend to spend more time together than people in a choir.

Other than a submarine, I think an aircraft carrier counts as "swimming" in virus. 1156 case. 3200 crew plus 2500 air wing. I don't know how many air wing were on board. Suppose there were 5000 in total so you have 23% infected. If they truly were swimming in virus that means 77% of a young mostly male population are immune without an infection and without a vaccine.

7. This also seems to imply Swedish policy does not matter very much.

Except to the dead, but they are beyond caring.

At least for this round, Sweden, the U.S. and France will end up with the same number of per capita deaths. Not as low as Finland, Norway, Denmark and Germany but not as high as Italy, Spain, the U.K. and Belgium.

"5. Are airplanes actually pretty safe for Covid-19 risk? (Not endorsing this piece or offering it up as advice, I do not myself know one way or the other. Any opinions here?)"

The author is a self described "assistant professor of exposure assessment science at Harvard T.H. Chan School of Public Health ".

But he references Tuberculosis instead of the SARs research. Which seems baffling, since obviously SARs is far more similar to Covid19.

"After one flight carrying a symptomatic person and 119 other persons, laboratory-confirmed SARS developed in 16 persons, 2 others were given diagnoses of probable SARS, and 4 were reported to have SARS but could not be interviewed. Among the 22 persons with illness, the mean time from the flight to the onset of symptoms was four days (range, two to eight), and there were no recognized exposures to patients with SARS before or after the flight. Illness in passengers was related to the physical proximity to the index patient, with illness reported in 8 of the 23 persons who were seated in the three rows in front of the index patient, as compared with 10 of the 88 persons who were seated elsewhere (relative risk, 3.1; 95 percent confidence interval, 1.4 to 6.9)."

Reference diagram:

Image of airplane layout and infection spread :

yes, I had a post about this weeks ago. It's the infamous SARS related Hong Kong Beijing flight ( AIr china flight 112).
It's pretty infectious in an airplane.
There are other studies showing that masks were effective in airplanes ( If people keep them on).
They need to filter the air circulation ( HEPA filters) and manage the airflow so that it goes from low to the ground to the ceiling with no lateral flow.
I think it's doable

There's also that article a few weeks ago showing where tables and chairs were located in a restaurant, and who got sick and who did not. (People sitting downwind -- there was an air conditioner blowing the air a certain direction -- of the infected person tended to get stick.)

Granted that was a restaurant, not an airplane. But though airplanes do exchange their air, that also means that the air moves from the sick person to whoever is near them.

But isn't TB very contagious once someone is at the coughing stage of the infection? I think that's why he used it.

But the line that the air filtration system is similar to an isolation room isn't very comforting. Last time I checked, there's just the patient and health care workers that enter the isolation room, and they're decked out in PPE. It's not the same as 100+ people all sitting packed together in the isolation room, sharing the air and aerosol before it hits the filters. And then each time the sick person coughs or sneezes or talks, we get a new batch of the virus to breathe in for a while before it gets filter. Again, that's not how things go down in the isolation rooms.

Sweden not getting to herd immunity quickly by definition means they are not spreading the virus very quickly. Just an attempt to change the narrative so they can keep calling Sweden wrong for not going along with lockdown. Spread in the +65 group seems relatively low which is the goal for a herd immunity strategy.

It will be interesting, after years of insisting that socialized healthcare would work in America as it does in Scandanavia, if the drive-by media is forced to admit at some point that the Swedes are making it work, but their culture is so different it wouldn't apply here. No doubt the NPCs would not notice the apparent incongruity.

Don't you worry Steps Have Been Taken to ensure that Swedish culture won't be different for much longer.

That's the other interesting thing, one wonders to what extent Sweden has the ability to enforce a lockdown, given the unrest in other European countries with large migrant populations. Is this a novel strategy or an admission of defeat? On the other hand, the Swedes suffer enough hand grenade attacks, rapes, etc. on a daily basis that perhaps the additional unrest caused by a lockdown would not move the needle much.

It is pretty important to avoid this sort of shifting about. Lockdowns were proposed to avoid *continued* exponential growth and flatten the curve. The idea was that "The Hammer" was the only way to flatten the curve.

Now they may actually hasten the elimination of the disease, but that is not how they were sold. They were sold as a way to avoid 10,000s to 100,000s death in countries. If they actually prevented single figure 1,000s of deaths of very old people, this is a huge goalpost shift!

And it presents a very different cost:benefit ratio.

This despite all the pro-lockdowners insistence that the exact same economic damage will be felt by Sweden as by others. It very obviously will not be the case that it is the exact same despite maintaining much more economic output, and frankly the very idea is clinging to absolute fantasy economic decline projections.

#8: Useful, but "k" is clearly as variable and endogenous as R0 is.

Maybe some people have the biological or genetic or whatever characteristics to be super-spreaders, by shedding more virus for a longer period of time, talking more loudly and longer, etc.

But clearly context and behavior matter too. Singing, temperature and noise level in meat plants, physical distancing or lack thereof, indoors vs outdoors, we still don't know though we have a long list of potential factors.

The useful part, though only if we get good evidence and that's going to take a lot of research, is behavioral recommendations -- or requirements? -- that will help. But they surely are not the only answer, there's even more cases that didn't start in choirs nor meat packing plants.

Speak softly and carry a big mask?

lol, I was in a store today and there was a guy talking very loudly ( He had a mask on), I was thinking does he have a hearing problem or he wants to infect everyone ?
There is a video with laser illumination showing how many more droplets you exhale when talking loudly. Also singing like choir singing is not good in confined places ( it's forceful exhaling)

This points that you just need to suppress large indoors events and places like bars where people have to talk loudly because of the music. That does most of the prophylaxis required.


Decision to force nursing homes to take in COVID patients will go down as worst policy of pandemic. Amazing how "hero" Andrew Cuomo responsible for worst policy of the entire crisis.

Yes, it’s terminally dumb. I am impressed by how Hong Kong handled it. They get an A.
This is the way to do it because even in normal years they have to deal with flu and pneumonia.
From the article.
“He added that all nursing homes had a trained infection controller and underwent emergency drills simulating an infection outbreak four times a year so infection control becomes “a well-worn practice”.

4., 7. I had forgotten that it was Cowen who coined the term "mood affiliation". It seems there are lots of moody people when it comes to the pandemic. That a contagion would be politically divisive indicates just how stupid people are. And that includes the so-called smart people who aren't smart but are moody.

The near-immediate ordering of the framing and debates in the US into partisan lines is among one the more dissappointing (and likely unhelpful) aspects of this.

We were of course treated to armed dingbat protestors who lost more freedom using their cell phones that they do wearing masks. And a dysfunctional child-President raging at Democratic governors while ignoring the Republican ones wrestling with the same problems.

This event also was the final nail in the coffin in the relationship between the GOP and science.

But the polarization of this has just begun. I shudder to wonder what will happen next. The idea of the infections laying down for the summer (during the election season) only to roar back right before the election strikes me as a terrible potential scenario.

For the record:,_2020

George, you hit again with uninformed trolling.

Applause for you, my good Comrade.

In a troll scoring, a link to ballotpedia is going to fare better than your ad hominem

Ann Althouse this morning:

I listened to about 3 minutes of CNN this morning as I drove home from my sunrise vantage point...

... and I feel like I can sum up what cable news will be saying over and over today on the topic of ending the coronavirus lockdown in the various states:

Democrats are saying that we're all in this together and this is beyond politics but Republicans are playing politics. Republicans are saying that we're all in this together and this is beyond politics but Democrats are playing politics.

Babylon Bee:

"Study Finds Anyone Who Makes A Different Decision To Wear A Mask Than You Is A Brainwashed Sheep"

Seriously? You complain that this is politicized and then write a political screed? Physician, heal thyself!

Amidst the sea of baseline partisan dysfunction, the President and his gang of armed idiots have gone above and beyond.

In times like these, we expect to President to transcend. This one doubled down.

The scientists he waged a war on were not partisan, nor was their advice, many of them were Republican appointees in fact, yet he turned defying science into a partisan litmus test, and masks into a partisan protest.

Most of the governors, including the score of Republican governors, who issued stay at home orders, were not trying to make it a partisan issue. yet that is exactly what he did, with his insane and incredibly reckless "liberate" tweets, for just one example.

Poe’s law response.

To quote the Hillary: Honestly at this point, what difference does it make ?

I am ever grateful to have you as my shadow

Woosh on Poe’s Law.

Like I said at this point what’s the difference between a troll and batshit partisan?

Little to none

I really admire how you follow me around so persistently and regurgitate little quips you learned on Wikipedia.

Do you have some form of random quip generator, or are you repeating the things here that other posters say to you elsewhere?

"Seriously? You complain that this is politicized and then write a political screed? Physician, heal thyself!"

That's one of those cases that you aren't really sure if the person is being sarcastic, trolling or is just genuinely too deep in the bubble to understand an objective perspective.

Is it possible for the partisan-ization of an issue to be imbalanced. It's entirely commonplace for a person to be going about their merry way doing their business, and find themselves the target of a partisan outrage circus - thier ordinary affairs suddenly the target of a hyped-up Breitbart hit piece, for example. Actually this happens all the time. Actually, this happened this time.

But for you to be able to comprehend that would require, oh silly me.

I mean you could deal with the content. Nah, that's crazy talk, troll on MacDuff!

actually keep digging

8. Looks like a very plausible explanation for heterogeneity.

Surely this means that mask wearing is especially important, especially in the very earliest stages, before testing and tracing can be scaled up. Just one mask on the right mouth, even an imperfect cloth mask, might snuff out a superspreader cluster before it happens. Maybe even flip the outcome weeks later by orders of magnitude. Was the West Coast smarter than New York or just lucky?

That makes the early advice from Fauci especially unfortunate. March 8 on Sixty Minutes: "People should not be walking around with masks." "There's no reason to be walking around with a mask."

And here's the Health editor of the Guardian on February 5, relaying what UK health officials were saying at the time ( ):

(0:55) “The advice is different in different countries, and because we have so few infections in a country like the UK or in the United States, on the whole, it's not really a sensible precaution to wear a mask.”

On the contrary, the early stage, when very few people have it, is the best possible time to mitigate.

In every Western country public health officials were reading from the same stupid script, giving the same terrible instructions not to wear masks. The head of the Chinese Center for Disease Control and Prevention called this "the big mistake".

Surely these well-meaning fools, who lied intentionally "for the greater good", hoping to preserve masks for first responders but never even mentioning the option of homemade masks, must have killed more people with their words than all dumb pronouncements combined from the mouth of Donald Trump.

What would be interesting now would be to redo the analysis of link 1. (mask wearing) in light of link 8 (clustering).

A universal mask requirement would be synergistic with anti-clustering measures. Wearing a mask changes your behavior and lowers the cognitive load of compliance with public policy. While wearing a mask, you are probably not going to spontaneously gather into large groups. The salience of pandemic mitigation is high. It would be silly for a bunch of people to get together while wearing masks. That is aside from practical considerations: they can’t eat, their voice is muffled when they speak with each other, etc...

Are cloth masks effective though? I've heard from some doctor friends that they are not really effective because the viruses are too small to be caught in the cloth, and they could actually facilitate virus transmission if they are reused and thus provide a surface for viruses or if they cause people to go out more when they should be staying home. The study linked to is about surgical masks, not homemade cloth masks.

Government leaders clearly messed up when they told everyone early on that masks didn't work, but we should be careful not to make to overcompensate in the other direction.

They have some effectiveness. Cloth masks are about half as effective as surgical masks.
The virus is not airborne by itself. It is in droplets of varying diameters. These are somewhat intercepted by a mask.
Do this simple experiments.
Put on a cloth mask and spit. See if you hit a target with the same amount of spit as without a mask. The mask certainly blocks some.
Also there’s a video of laser illumination of speech droplets with and without a mask showing the mask blocks a lot.


I could not find a description of the mask type being used. Any idea on that?

It’s a makeshift mask, not an N95.
They say this in the text:
“ When the same phrase was uttered three times through a slightly damp washcloth over the speaker’s mouth, the flash count remained close to the background level (mean, 0.1 flashes);

Cloth masks are NOT just half as effective. Studies have shown that a moderately thick cotton mask filters 70% of viral-sized particles. Surgical masks filter 95%. This is speaking strictly of outward virus emission by the way. I protect you, you protect me. Another benefit of cotton masks is that they are washable. See my main post further below on how combing cotton and chiffon (a cheap material) or silk achieves 95% filtration. Even if everyone just wore cotton masks, social distanced, and avoided gatherings, that would help a lot.

Addendum: I must add that the cotton + chiffon or silk approach has the added benefit of protecting you, not just protecting others. This is because it has better inward filtration as opposed to more outward filtration.

There are many studies and they don’t all agree. I would not insist on a precise number. Here is a review of studies that found large variation ( from 9 to 99%) in filtration efficacy.
This is not surprising as it’s difficult to measure and the methods vary.

Come on now. I looked at the meta-study you shared. That’s a misleading takeaway. 9% filtration is the rock bottom among several studies, and was likely arrived at by measuring filtration of the smallest droplets, which constitute a minority of the total particulate mass that is emitted. 70% is a more accurate number, reflecting filtration of overall droplets (across all sizes) filtered by a thick cotton mask. Wherever there is heterogeneity in mask quality, the government can give pointers to citizens in order to maximize the protectiveness of masks as a public health measure.

Arguing about whether cloth masks work in the context of COVID-19 is as silly as arguing about whether clothes keep you warm in the winter. The guy wearing jeans and a t-shirt says no, they guy wearing flannel-lined pants and a flannel shirt over his t-shirts says yes.

What's interesting is the comment "we should be careful not to make to overcompensate in the other direction." This isn't dosing everyone with hydroxychloroquine, which will likely kill some people. The only down side to wearing masks is that until you get used to it it's somewhat uncomfortable, it fogs up your glasses, and a too-restrictive mask can impair breathing. What I see is a lot of people saying there's too little clarity of how well masks work, and arguing about infectious droplet size, so they write off the entire idea.

The typical human response is "it's too confusing, the experts disagree, so I won't bother." Meanwhile, what might be the single most effective (and cost effective) tool for mitigating COVID-19 and getting people out of their homes is being largely ignored and even denigrated.

Rebuttal to number 7: "We aren't at seven percent [infection rate in Stockholm] now. It was seven percent around week 15, so that is quite a long time ago. These people were immune in week 18 [the week ending May 3rd], that means they fell ill at some point in week 14 or 15. We are somewhere around 20 percent plus in Stockholm now," Tegnell told journalists at the press conference.

Why on earth is age broken down into only THREE categories???? I've seen this in other contexts too, if you do Google's self-eval for Covid risk, the only break down is age < 18, 18<age<64, and 64<=age!! It doesn't seem to be a sample issue in the Sweedish study, as n==1100.

#7. At 3,831 COVID deaths as of today, you wouldn't expect them to be near heard immunity, unless the IFR were very, VERY low. Recent estimates I've seen put the IFR for COVID, conservatively, at around 0.6 or 0.7%. That suggests about 500,000 to 600,000 Swedes had been infected already, which is right around the 5-6% of the population that the antibody survey shows.

Without an effective treatment, it seems you need 60% of a population infected to have effective herd immunity (at least that's the number tossed around). That would mean you need around 40,000 Swedes succumbing to COVID. As we can't change the IFR without treatment, once we know the IFR, we just need to track the dead to see how close herd immunity is.

HOWEVER, the number of dead *could* vary depending on *which* 60% you infect. The Swedish policy, as I understood, was to prioritize (not quite deliberately) infection of the young so that they could shield the old, although I understand that approach had failed as a result of infections spreading in nursing homes and containment efforts failing there.

Seems like NYC should, in theory, be a lot closer to herd immunity. There, by contrast, it does appear the old were disproportionately infected through the "policy" of discharging COVID patients *into* nursing homes.

The Swedish policy still seems the most sound. It did encounter problems in implementation, unfortunately.

There is a lag for antibodies, so these numbers are likely a few weeks old. That indicates the IFR is significantly below 0.6 or 0.7%. That is likely because the disease is far more prevalent in their youthful population than it is in their elderly population.

It's probably care homes specifically as well rather than elderly alone.

Higher spread within hospitals and care homes is a big confound to working out population level IFR from excess deaths/(est pop with seroprevalence). For example, if you have a spread of X in the general population, but the a spread of 2x in a population that's 4x at risk compared to the general pop, then you're going to end up with skewed estimates of fatality.

yes, for sure. The CDC has a spreadsheet of Covid-19 deaths by age.
Out of 69,000 US deaths a staggering 60% are over 75.
If you're very ineffective and let the very old get infected disproportionately, then your IFR is going to look very bad.

The people who belong to the 7% of Stockholmers with antibodies must have fallen ill with the virus sometime around the first couple weeks in April at the latest. Going by the rate at which it spreads we are probably looking at about 20% in Stockholm right now according to Tegnell. At this rate Stockholm might reach 40% by June or July.

As Tegnell said that, he's a serious enough guy about evidence that I would guess he would not say it without that.

Still, in Sweden, the excess death rate has really fallen off since April peak, so if the disease is working its way through the population, then there is probably something to the idea that the disease was most likely to take hold in and kill the sickest first, and hence IFRs will reduce over time.

That would make sense if true; chance of infection of anything probably higher in systematically less healthy people. Healthier people less susceptible in the first place (even adjusting for spread in care homes and hospitals).

But we don't know if it's still working through the population. Further updates of seraprevelance needed.

7. The Swedish news isn't remotely surprising. A quick back-of-the-envelope calculation indicates their IFR is about 0.75 with that percentage of sero-positives, which is exactly what one would expect from the total deaths. COVID-19 would have to have an IFR out of a Ioannidis fantasy preprint (i.e., something like 0.05) to be approaching herd immunity.

It's looking like they're getting the worst of all worlds. Their per capita death rate is far far higher than their Scandinavian neighbors, they're miles away from herd immunity, and the Swedish authorities are projecting an economic hit on par with the rest of Europe.

Yes, except your calculations are all wrong because you used death and infection date 7 weeks apart to do it. Too bad.

You are annoying. 0.75 means 75%.

Brilliant responses, guys. When I wrote IFR of 0.75, I obviously meant as a percentage. If you want to repeat my calculation, you divide the deaths by .0075. You then divide that number by the Swedish population, and you get a percentage of infections that largely matches the percentage of sero-positives. Not too hard to figure out, is it, Brian?

And Joel, the sero-positives are from week 18, which ended May 3. Deaths lag infections, often by a couple of weeks, and the Swedish officials are well known to be delayed in when they record death data. Too bad, indeed, at least for the Swedish plan.

Sweden deaths by midpoint of week 18 - 2697 (April 30).

All population serological prevalence from combining figures in tweet with demographic pyramid: 5.5% (

5.5% of Sweden's 10.3 million is 550,000. 2697/550000 = 0.5% IFR.

(0.6% at the highest, assuming some undercounting of 20%, which is about the highest possible excess mortality not attributed to Covid19 that I've seen for Sweden).

That's apples to apples, as serological lag is about as long as it takes to die (anyone comparing current deaths to seralogy at a point weeks prior is flatly dishonest!).

About what you'd expect from a 0.7ish% all-pop IFR and relatively successful shielding of the over 65s (lower prevalence in their example).

But if they'd shielded the care-home residents, it would of course be quite a bit lower.

(However, another factor that may lay it lower is that they may not actually have shielded the elderly. May be that elderly do not develop reliable signal at quite 100% rate... But for the moment, let's assume that they do).

Btw, anonymous claimed that Sweden's was experiencing far higher relative IFRs than was typical for the disease from "overstressed healthcare".

Well, I guess he and others of the same opinion must now think the true IFR with "unstressed" healthcare is half again of that 0.5% or something like this...

The Yemeni rial has never been worth much. There has always been a de facto 2 currency system in Yemen, the rial and the US dollar. When I was there a decade ago the largest bill, the 1000 rial, was worth about $5. If you wanted to buy something a little expensive it would take literal bags of Yemeni currency to get it done. The US $100 was used instead. You could get them in ATMs. The Yemeni government also used the US dollar for oil revenues so it bought everything from other countries with dollars. Now the currency is worth even less and the rial is split I’m sure the US dollar is even more important.

1.) Finally Tyler gives due attention to masks. Masks + social distancing + quarantine of at-risk population w/subsidized deliveries = re-opening the economy + saving lives = best of both worlds

Everyone please note, however, that the study that Tyler linked to states that at least 80-90% mask-wearing is required to nearly eliminate the virus. And that’s with surgical masks. There is no way around mandating, by law, that everyone wears a mask, and then providing every citizen at the very least a washable cotton mask (while ramping up production of surgical and N95 masks). One approach which I’ve mentioned before is to give every citizen 1 cotton mask and 1 chiffon or silk mask (chiffon is cheaper). Cotton would block large particles, and chiffon or silk would filter small particles. Public officials are taking too long to follow the science on population-level PPE. We haven’t even picked the low hanging fruit. Get masks out to people now and require them to wear them. Period.

I skimmed the paper. I think it says with 80% compliance you can use a 50% efficient mask which is not as good as a medical mask which might be 58% efficient. I wonder if the problem is a reluctance of high status people to lead by telling people to go for the low-hanging fruit of homemade masks. Recommending anything homemade is an admission of failure to prepare. Reduced to wearing their wives' panties on their faces was not something Western civilization was willing to countenance.

Epidemiologists don’t seem to be freaking out about the lack of a population-level PPE strategy, even though that should be the keystone of our approach to dealing with COVID-19. Why is that? Are they worried that us proles would make a run for medical PPE as soon as masks are required, depriving the medical Brahmins of their extra-extra-backup supplies? I would have noticed by now if most epidemiologists were screaming “MAAAASKS” from the rooftops. This is really insidious, because as you mention cotton masks are completely fine. The mere possibility that medical professionals lose redundant supply (which won’t happen) is being heeded more than the potential to save tens of thousands of lives and the economy.

> Billions of people travel by plane every year, yet there have only been a handful of documented disease outbreaks attributable to airplanes in the past 40 years. If planes made you sick, we would expect to see millions of people sick every year attributable to flights. We haven’t seen it because it’s just not happening.

Anecdata, but I get sick with >50% probability when I fly cross-country.

The way that this article is phrased "documented disease outbreaks attributable to airplanes" makes me worry that there's a seeing-like-a-state thing going on. Airplanes could reliably spread things like the common cold without this causing "_documented_ disease outbreaks" because nobody documents _common cold_ outbreaks.

Reading farther in the article, I see they're addressing this concern

> Every time you fly, you may also take a cab, bus or subway; stand in long lines in the airport; eat unhealthy foods; sit for extended durations; spend time in spaces with hundreds or thousands of other travelers; stay at a hotel or friend’s home; arrive in a different climate and change time zones, disrupting your sleep. All of these factors are known to affect your immune system.

Taking this as true at face value, I suppose they are _technically_ correct, which is the best kind of correct but not the only kind of correct. If they are saying "actually airplanes are super safe for disease spread" but follow it up with "yeah, sure, people reliably get sick when flying, but really it was the crowd at the TSA line that made them sick" then I'm not sure that's relevant for the actual discussion. It's like saying "jumping off a building has never been documented to kill anyone. It's the sudden stop at the end of the fall that kills you".

2) Robodog to sheep: "You have 20 seconds to comply."

# 3. The biohackers lament the price of drugs. They never seem to understand that it’s not the cost of production-of this particular drug but the cost of development plus the amortization of development costs for all drugs that fail + the profit necessary to attract investors.
Similarly the marginal cost to Microsoft of streaming you their nth copy of Word is close to zero.
They don’t charge zero for that copy.

5. It would depend on the airflow directions and the air velocity. I suspect it limits the spread but doesn't eliminate it. The 2003 flight, are there any 17 year old aircraft running? Not sure.

There seem to be a few methods of propagation, and it is confusing. Hospitals can be, but they reacted soon and hard and managed to avoid the problem. Care homes are bad, a low budget hospital essentially, with usually immigrant workers who likely would have been exposed via travelling relatives. But not too complicated to sort out, simply a matter of focus.

Meat cutting operations where large numbers of people, same characteristics of immigrant workers, in a humid cool space working close to someone else, day in day out.

And the interesting restaurant air velocity and flow situations. This is what caught my attention. What if it is a situation where large distributed air systems spread the disease? Work from home got people out of those buildings, but I understand that in cities apartments have common air systems. Is that the case? That could be a problem.

Large stores are different again with the high ceilings and not a cross flow situation.

And being outside is less of a problem it seems.

Lots to sort out with this thing, and I suspect solutions will be beneficial for future less dangerous viruses.

Air conditioning systems are hot weather and the air passes through a wet coil, vs using these systems during the offseason when the coils are dry and can pass particles easily. Filtration in these systems typically aren't going to filter something as small as a virus.

Yes, but the virus is not free floating. It’s in solution in droplets that are much bigger.
I believe the virus needs to be in aqueous solution, to apply an external pressure otherwise the pressure of the capsid inside would cause the virus membrane to break and the virus gets inactivated. What about an HEPA filter. They’re rated to 0. 3 um. That should do it.

Regarding #5, “The Times learned of at least 15 [airline] workers who have died from COVID-19 from April 5-13"

7. Herd immunity not working and lock downs not working seem to be two sides of the same coin.

Blah, blah, blah. Acres of comments from not a soul who has any idea of what he's talking about.

8. Infections are generally higher among migrant workers, so I read. They live in crowded conditions generally. Would explain meat packing facility workers maybe.

In olden days, we would quarantine households, not entire communities. What we have now is extreme hysteria fomented by media and policy wonks. And of course leftist politicians who want to tank the economy and destroy the financial system so they can nationalize the banks and seize everyone's money.

Ya! What he said!

Airplanes are safe. Bourgeois and elite classes can continue to engage in fossil fuel-burning international travel. Also, there is no compelling reason for more than six inches of available space from your fellow passengers.

Churches, otoh, are literal hotbeds of infection.

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