
Preliminary test results suggest 21% of NYC residents have Covid antibodies - kgwgk
https://www.6sqft.com/new-york-covid-antibody-test-preliminary-results/
======
aazaa
> In his press conference today, Governor Cuomo revealed the preliminary
> results of a first-phase antibody test that surveyed 3,000 New Yorkers over
> two days in 19 counties at 40 locations that included grocery and big-box
> stores. The sample suggests that 13.9% of New York State residents have the
> antibodies, meaning they had the virus at one point and recovered. Of the
> regions tested–Long Island, NYC, Westchester/Rockland, and the rest of the
> State–New York City had the highest positive rate at 21.2%. The potential
> good news to come to light is that the death rate may be far lower than some
> estimates, at 0.5%.

This still is not a random sampling. It only samples from shoppers at grocery
stores and big-box retailers. Imagine doing the same study, but of people who
ordered groceries online only. Would you expect to see big differences in
exposure rate? I think so.

The study itself isn't linked anywhere, nor have I seen it elsewhere. Science
is all about the details. It's not hard to imagine half a dozen ways that the
bottom line result of this study could have been skewed by decisions made by
the study authors and ground team.

~~~
TheBlight
Sure all of these studies are potentially flawed but they're all generally
pointing in the same direction. There are many more infections than we know
about and the CFR is not anywhere close to the actual IFR.

NYC is an outlier with a 21% infection estimate but for the rest of NY
(outside NYC metro/Westchester/LI) the estimate is 3.6%. Santa Clara estimate
was 3%. LA County estimate was 4%. Seems like a trend is developing.

~~~
Karrot_Kream
> Sure all of these studies are potentially flawed but they're all generally
> pointing in the same direction

That's unfortunately not the way statistics works. Combining multiple bad
tests just makes the results incorrect or highly uncertain; the devil often is
in the details. The Stanford/Santa Clara County study is a good example of how
the details can really undermine a study.

Things do indeed seem to be converging to the idea that the CFR is not near
the IFR, but none of this is new news, and the IFR remains very close to what
most epidemiological predictions indicated early last month. If anything, it
confirms that COVID is a difficult beast to tame.

~~~
TheBlight
We don't have perfect studies and perfect data but calling these tests "bad"
seems slightly unfair. They give us an imperfect but useful snapshot of what's
going on. But thanks for the condescension. I'd expect nothing less on HN.

~~~
CydeWeys
The study is dramatically over-sampling exactly the people who have the most
potential exposure to COVID-19, and dramatically over-sampling the people who
don't.

This could easily be way off. It's not testing the people who aren't home at
all, and it has a low chance of only testing the people who leave home rarely,
only when strictly necessary. It's mainly finding the people who leave home a
lot.

~~~
varenc
I think the overwhelming majority of people are visiting grocery stores to buy
food. (Or have someone in their household doing it)

If the studied presume this then it makes more sense.

~~~
CydeWeys
You can't assume that. I know plenty of people who haven't left their
apartments in a month plus, because they're having groceries ordered in.

And you completely missed the point that people who are going outside a lot
more often are both (a) more likely to have been exposed to COVID-19, and (b)
more likely to be encountered by your survey. If there are e.g. 700 daily
shoppers and 700 weekly shoppers going to a given store, then if you go on one
day and sample every shopper you're not going to get half and half by
population as you'd need to for a true random sample; instead, you're going to
get 700 daily shoppers and only 100 weekly shoppers! This is a hugely biased
sample!

~~~
cm2187
The study wasn't one day but one week, and even then, I assume they wouldn't
be stupid enough to collect blood from the same person over and over.

~~~
CydeWeys
There's more than one store in NYC. People shop at a variety of places. Daily
shoppers are likely not going to the same store over and over every day. Even
during this pandemic I've hit up several different grocery stores and shops,
because some things are hard to find.

------
ccleve
This study doesn't appear to suffer from the same methodology problems as the
Stanford study of a few days ago. In that study, they recruited people through
Facebook, and reported an infection rate that was low enough that it could
have been caused by false positives.

Here, it's closer to a random sample, but more importantly it shows really
high rates. Those rates overwhelm any error due to false positives.

Also, it shows numbers that are in line with our intuition. It shows higher
infections in NYC, and higher infections among blacks. That reflects what the
hospitals are seeing.

This study may well be really good news.

~~~
tunesmith
Sorry, can someone spell out how this might be good news? 21% is still a long
way from herd immunity, and NYC's hospital system has been severely strained
getting to this point. On top of that, the hospitalization rate still seems
disproportionate to someone getting the flu - maybe it's five times as fatal,
but it's > 5x the flu hospitalization rate. It's not like the virus has
_become_ less dangerous, we're just realizing how dangerous it has been, what
with the impact we've already experienced.

Besides, generally if a virus is less fatal than previously expected, it means
it's more contagious, meaning that much harder to get to herd immunity.

Good news would be things like: evidence the virus has mutated into something
less severe; evidence of an anti-viral treatment that improves outcomes for
everyone so it's not as big a deal to catch it; evidence that community spread
has halted in an area and the boundaries are controlled so people in that area
can feel secure they won't catch it; evidence of an impending vaccine.

Is this good news just because we're finally establishing that people have
caught it once can't re-catch it for now? I guess I can see that as good news
but that is so expected that it's more like it would be horrendously bad news
if we found evidence that recovered people _didn 't_ have antibodies. But
generally I don't really see what policy impact this has, other than
identifying a pool of workers that can go work in meat-packing factories
without fear of catching it again.

~~~
revnode
> Sorry, can someone spell out how this might be good news?

It's good news because it strongly suggests that mortality is much less than
previously suspected. There were numbers floating around from anywhere between
10% to 3% a few weeks back. A mortality rate < 1% is very good news because it
means fewer people will die in the long run.

~~~
kgwgk
> mortality is much less than previously suspected

Mortality remains pretty much as suspected already two months ago:

“Based on these available analyses, current IFR estimates10,11,12 range from
0.3% to 1%. Without population-based serologic studies, it is not yet possible
to know what proportion of the population has been infected with COVID-19.”

[https://www.who.int/docs/default-
source/coronaviruse/situati...](https://www.who.int/docs/default-
source/coronaviruse/situation-reports/20200219-sitrep-30-covid-19.pdf)

~~~
zaroth
Two weeks _after_ that the WHO released a widely cited report claiming a
fatality rate of 3.4%.

“Globally, about 3.4% of reported COVID-19 cases have died. By comparison,
seasonal flu generally kills far fewer than 1% of those infected.”

[https://www.who.int/dg/speeches/detail/who-director-
general-...](https://www.who.int/dg/speeches/detail/who-director-general-s-
opening-remarks-at-the-media-briefing-on-covid-19---3-march-2020)

~~~
tunesmith
CFR will be higher than IFR due to undercounting infections.

------
guscost
While this is great information, a few facts will still confound attempts to
speculate based on this number:

\- The production of IgG antibodies is mostly delayed until after an infection
is cleared.

\- This is a random sample of people who were outside, it's not representative
of the total population.

\- Non-trivial numbers of people may never develop detectable antibodies for
SARS-CoV-2:

[https://www.medrxiv.org/content/10.1101/2020.04.17.20061440v...](https://www.medrxiv.org/content/10.1101/2020.04.17.20061440v1)

[https://www.medrxiv.org/content/10.1101/2020.03.30.20047365v...](https://www.medrxiv.org/content/10.1101/2020.03.30.20047365v2)

~~~
CubsFan1060
If I follow, your first and third points would indicate the number may
actually be higher?

Additionally, does your third point also indicate that they will never be
immune, or just that we won't be able to test for it?

~~~
guscost
All three could push the true total higher, but number two easily could push
it lower instead. And I'm not a microbiologist but I think lack of antibodies
only means that we won't be able to test for past infection. The seronegative
patients (determined by a very precise method for measuring antibodies) in the
second cited paper were still able to clear their infections.

------
mrb
If this study is accurate, then 1.8 million NYC resident are infected. So 15
411 deaths (as of today, including 5 121 probable deaths) suggests COVID-19
has a fatality rate of MINIMUM 0.9% which is in line with previous estimates
(between 0.5 and 1.6%) and this is MINIMUM 9 times more fatal than the flu
(0.1%).

Edited to add "MINIMUM", as there is a lag between case detection and death (I
should have known better to mention it, as I blogged about it:
[https://blog.zorinaq.com/case-fatality-ratio-
ncov/](https://blog.zorinaq.com/case-fatality-ratio-ncov/))

~~~
DeonPenny
It's also lower than the 3% that was predicted that people used to justify the
shutdown and closer inline with the swine flu or rotovirus.

~~~
empath75
Nobody ever seriously suggested it was 3%. The estimates were always around 1%

~~~
DeonPenny
[https://www.cnbc.com/2020/03/03/who-says-coronavirus-
death-r...](https://www.cnbc.com/2020/03/03/who-says-coronavirus-death-rate-
is-3point4percent-globally-higher-than-previously-thought.html)

I mean there were articles like this all of march. I'm not saying the WHO or
CDC might of said something different but lets acknowledge there were articles
proclaiming a 3% death rate.

------
daxfohl
I find myself reconsidering the original proposition by England to isolate the
most vulnerable for a couple months and let the virus work its course through
the less vulnerable population.

If death rate is substantially lower among the under 50 crowd, this could work
its way through with a fairly low death toll, and result in a herd immunity
within a couple months. This slow burn approach we're doing however seems
possibly to be the precise worst way to handle it, leaving the virus in the
population for as long as possible, reducing the ability for our vulnerable
population to avoid it.

Note I think the best possible solution is a complete lock down for a couple
months until the virus is more or less eradicated, as Wuhan did. But I don't
think it's a realistic option in our society.

~~~
jdm2212
The outcomes aren't just death and recovery. There's also the possibility of
long-term heart, lung, and kidney damage. And the blood thinners used to
prevent coronavirus blood clots can cause brain bleeding. Those happen in
younger people, too.

And realistically there's no way to isolate those over 50. They generally live
with, work with, or are cared for by younger people.

~~~
taeric
This feels like fear talking. As more data comes in, we are seeing more people
with no affects. Not just mild, but nigh non existent.

It is agreed that something gives people severe cases. Severe includes death
and recovered with damage. We don't seem to have data letting you know who or
what would land there.

~~~
cryoshon
we have absolutely no clue regarding the long-term impacts of exposure to this
virus for asymptomatic people or otherwise.

we cannot gamble with our future so carelessly on the basis of preliminary
data. here is a vignette to explain why.

once someone is infected with HIV, most people experience flu-like symptoms
for a week or two which then resolve either with or without treatment. in some
people, the virus is cleared so effectively after the initial infection that
they will test negative for HIV. then, over the span of months and years,
their immune system is silently and entirely asymptomatically destroyed,
leaving them none the wiser until they progress to AIDS and get extremely
sick.

COVID hasn't given us any indication of similar activity. but we know so very
little that we can't take the risk, especially not with millions and millions
of people. i will also note that we are unlikely to rule out these kinds of
hypothetical risks anytime soon. so caution is our only defense against
disaster.

~~~
easytiger
> hasn't given us any indication of similar activity. but we know so very
> little that we can't take the risk

There's little reason to believe it's significantly different to any other
Coronavirus. Speculating that's it's suddenly going to be aids++ is pointless
scaremongering.

The main* reason it was a "big deal" was the lack of common immunity thus
leading to potentially rapid spread. Deaths in the vulnerable from the side
effects of this kind of thing are perfectly normal and perfectly well
understood and there is very little treatment

~~~
ericb
I don't think necessarily aids++, but speculating about long term effects is
not pointless, or unreasonable.

[https://www.thestar.com/life/health_wellness/2010/09/02/sars...](https://www.thestar.com/life/health_wellness/2010/09/02/sars_survivors_struggle_with_symptoms_years_later.html)

~~~
easytiger
As with any viral pneumonia

~~~
ericb
Any _novel_ viral pneumonia.

A garden snake and a cobra are both snakes. Belonging to the same category
says nothing about the potency of their bite. We have no idea what kind of
snake this is yet.

~~~
easytiger
We have a pretty good idea

------
zyxzevn
Good news. Herd-immunity is growing.

Also, this means that the death-rate is far lower than reported. And this is
nice too. Maybe we can save people by starting the society again.

In other news, we see that hydroxychloroquine is actually working according to
doctors. But there was a very bad study that claimed that it caused 2x as many
deaths. It should have said instead that it was mainly used on patients that
were close to death. Here is a good analysis of that study.
[https://www.youtube.com/watch?v=dLSYRqcg0wo&feature=youtu.be...](https://www.youtube.com/watch?v=dLSYRqcg0wo&feature=youtu.be&t=12m13s)
Bad studies like this wide published one show that science is not immune to
political agendas.

~~~
mantap
The presence of antibodies is not sufficient for herd immunity. For herd
immunity you need those antibodies to stick around.

------
sjg007
Is this antibody test specific for covid-19 or would it be positive on other
coronaviruses? That's a real concern since the other 4 coronaviruses are
endemic.

~~~
hitchhiker999
What's terrifying is with all these professional analysts in here, yours is
the first comment I've seen that asks this obvious question.

------
tangent-man
To assume the infection fatality ratio(IFR)is 0.5% from this is retarded. We
know that when covid-19 began to spread in South Korea at first it spread
among a younger population who were ignoring or at least not following
government advise so closely and taking chances the IFR was looking like about
0.7% to start with (In SK). We know this as SK kept excellent data / records
to begin with. We also know that the Diamond Princess with a more generally
aged population has a IFR of 13% +. We know this is a disease that adversely
effects the elderly and infirm (in the developed world) If you are over 80
getting covid you might as well play Russian roulette with a Magnum .45 .These
groups of people know there at risk, so if they have any sanity they are
staying the hell at home. So people who are going into the Grocery store in NY
city aren't representative of this population. This is why we are staying at
home mostly to protect the old and infirm. That's not to say you want Covid-19
yourself either because there's about a 5% chance you will end up in the ICU
(and an as yet undisclosed chance of death) even if your a member of the
Hungarian Olympic Shot-Putting team. This does kill young tough people, it
does happen but this is mostly killing the elderly and infirm. Why are people
so fecking retarded? I can't take this anymore!! Stay the Sm3g at home! It's
stopping the hospitals being overloaded.. It's buying us time to figure out
new treatments / how to treat this better.

~~~
apexalpha
Read an article that over half of Europe's Covid deaths might be from nursing
homes...

~~~
tangent-man
Sounds plausible. Do you have a link to that article? I'm not trying to bate
you, I'd genuinely like to read it.

------
glofish
Well, it looks like in the end that much-criticized imperial model might be
right on transmission rates but way off on the fatality rate and with that
predicted deaths.

It pretty much looks like none of the epidemiological models are reasonably
accurate on both, case numbers and fatally rates

~~~
guscost
If you're fitting a model to observations, they'll have something of an
inverse (but of course non-linear) relationship. So if your virulence
estimates are worse than your transmissivity estimates, or vice versa, the bad
measurement is going to push the model out of whack.

------
JamesBarney
> The reason the tests were randomly taken from those at grocery and big-box
> stores is that these were people not isolating in their homes and presumably
> not at work and therefore not essential workers.

~~~
chrisseaton
I don't understand - essential workers still going to work also have to eat,
and so go to grocery shops like other people.

~~~
istorical
The sampling location isn't meant to exclude essential workers, it's meant to
avoid only sampling essential workers.

IE: if you measured at workplaces that would capture only essential workers,
if you measure at people's homes during work hours, you get people who mostly
are quarantining, if you measure at a grocery, you might get a mix of both,
etc.

~~~
chrisseaton
> isn't meant to exclude essential workers

But is specifically says

> and therefore not essential workers

It doesn’t say ‘not only’ - it says ‘not’.

~~~
tree3
> presumably not at work and therefore not essential workers.

"presumably" is the key word. They aren't saying "definitely".

------
3fe9a03ccd14ca5
At what point have we scientifically reached "herd immunity"? Is it 50%, 90%,
99%?

~~~
grey-area
More like 50-80%, you just need spread to be impeded so that r falls below 1,
but for that many people to get it would mean very high deaths, in the US 1%
of 80% of 320m is > 2m deaths.

~~~
nullc
Keep in mind that if 21% of NYC residence have been infected this probably
implies R0 in that population was higher than in most prior estimates of R0,
which increases the threshold of immune people before R0 falls below 1.

~~~
votepaunchy
It also implies that the R0 of the already-infected population is higher than
that of the not-yet-affected population.

~~~
robocat
R0 varies hugely. The R0 for highly connected people meeting others regularly,
will be far higher than the R0 for people who only leave the house once a
week. The R0 in a crowded prison will be far higher than the R0 of rural farm
owners.

------
ineedasername
I couldn't find any detailed write up about their selection methods for
participants, only the basics of where they found them. Without that, it is
very hard to determine whether or not there's some flavor of selection bias:
If it is voluntary, and they do not screen out people who report having had
cold/flu symptoms, then they run the risk of attracting a disproportionate
number of people who volunteer because they're curious if their prior symptoms
were actually coronavirus. That would make it far from a random sample. The
fact that they sampled only people actually leaving their house is also a form
of selection bias: these are the people more likely to be exposed and may
represent a disproportionately high infection rate as well.

So I await further information.

That said, even if it's overall 0.6%, that is still 6x higher than flu, and
higher than H1N1 which had a CFR around 0.1 for areas with adequate health
care. (much higher when there was not adequate care, but that is not
dissimilar to Covid.)

So no matter what, no one should be walking away from this study saying "See
it's no big deal! Just the Flu/Cold etc!"

~~~
SketchySeaBeast
Do you have a source for the CFR of 0.1 for H1N1? I could only find this[1],
which is a much smaller number.

[1]
[http://news.bbc.co.uk/2/hi/health/8406723.stm](http://news.bbc.co.uk/2/hi/health/8406723.stm)

~~~
ineedasername
You may be looking at "settled" numbers when all was said & done and all facts
were known. That's not an "apples to apples" comparison with current covid-19
knowledge.

Here's my source [0] and the relevant quote, below. It is the CFR _during_ the
H1N1 pandemic, 10 weeks into it, which is why it is a much more appropriate
(though not perfect) "apples to apples" comparison with Covid-19:

> _" The overall case fatality rate as of 16 July 2009 (10 weeks after the
> first international alert) with pandemic H1N1 influenza varied from 0.1% to
> 5.1% depending on the country."_

[0] [https://www.cebm.net/covid-19/global-covid-19-case-
fatality-...](https://www.cebm.net/covid-19/global-covid-19-case-fatality-
rates/)

------
IkmoIkmo
They're trying to measure infection rates by analysing people who are more
likely to go outside, and more likely to be infected. There's no adjustment
for this confounder at all that I can see. Quick example:

Suppose there's a 10% chance of getting infected every time someone goes
outside. Suppose there's a million people of which half are type-A people who
go outside once this month, and half are type-B people who go outside 10 times
a month.

The type-A person will have a 10% infection rate. The type-B person will have
a 65% chance to be infected after a month. The average infection rate is
around 42%. Yet if you randomly select someone outside, odds are 10 to 1 that
it'll be a type-B person, and you'll get a far higher average of 60%, which
isn't indicative of the average person, only of the average person who goes
outside.

Second, the article then compares the infection rate to the mortality rate.
But the mortality rate does not include excess deaths. These are quite a bit
higher for NYC, about 30% or so it seems than the official figures. But even
this may be undercounting (or potentially, overcounting) the impact of the
corona disease itself. Other deaths might be much lower (e.g. traffic, murder)
or higher (e.g. untreated cancer).

Then there's the lag-effect. There's 150 thousand confirmed infected, 15
thousand dead. But the vast majority of confirmed cases are still active, not
recovered. They're confirmed because tens of thousands were hospitalised. Of
the incubated people, 80% do not come out alive. There's lots of people
fighting for their lives right now. Once those cases resolve, many will not
have made it. And that's just hospitalised people. Then there's lots of cases
who just got infected, and will be developing symptoms in 1-2 weeks.

The way exponentials work is that lag is way more important. In the first
weeks NY doubled every 2 days. That means if you have 10 thousand today
infected today, in 10 days that's 320 thousand. That's when people start to
get symptoms, and 10 days later people start dying from the symptoms. That
means your infection count can go into the hundreds of thousands or even
millions before seeing any death. But you can't conclude mortality figures
from that, at all.

In short, the 21% and the 0.5% conclusions are extremely premature and should
not be reported like this. It's good to report the measurements, in context,
but you can't draw the conclusions about the population or disease from it.

------
lettergram
I’ve continuously questioned the antibody tests...

My understanding (from NBC news) was that at least some of the antibody tests
were derived from a couple who were on the princes cruise. They never showed
symptoms, but tested positive. IMO it’s quite possible that they never had it
and those tests were inaccurate (right at the start of the outbreak, no
symptoms, etc).

Further, these antibody tests likely weren’t fully vetted nor were the samples
they derived it from. For instance how often does another coronavirus set off
this antibody test?

Personally, I’m just waiting to see. I actually do suspect 20% have been
infected, so it fits my expectations, but that’s not validation.

------
ummonk
0.2% of people in NYC has died from Covid-19, so this is exactly what we would
expect.

------
seemslegit
0.5% IFR is still very high, I wonder what the antibody detection threshold is
- i.e. is it possible that a lot more people have been exposed but don't have
detectable antibody levels ? Would it qualify as infection in the sense that
they are not susceptible for covid19 in the near term ?

------
duxup
It sure would be nice to find out the virus is far more widespread / exposure
is higher than expected if only that would seem to indicate that the light at
the end of the tunnel is nearer than we think ... and a lot of people have
been exposed and doing well.

------
m3kw9
For the people that thinks death rate is low is good news, it’s not when you
know how contagious it is, you then need to look at numbers, not percentage to
get a practical look at severity.

------
cm2187
Another datapoint suggesting the death rate of this virus is within 0.5%.

~~~
cozzyd
I had the opposite conclusion. There are between 10k-15k COVID-19 associated
deaths in NYC, depending on how you count (the higher rate is consistent with
the excess-mortality data, I believe). That by itself produces a range of
~0.56%-0.86% if you assume 21.2 % of NYC has been infected (larger range if
you allow for some error on the infection rate, obviously). Moreover, we don't
know what fraction of the currently-infected who will die have already died. A
reasonable guess might be 50%, which would mean that the fatality rate for NYC
is somewhere between 1.1 and 1.7%.

Either way, based on NYC, 0.5% might be a hard lower bound on the all-
population fatality rate (of course, maybe NYC is not a representative sample
for some reason)

~~~
cm2187
0.5% comes from Cuomo’s presentation [1].

Also your 50% seems very high to me. My understanding is that 50% is about the
death rate of covid patients requiring ventilation, so the overall death rate
of people hospitalised for covid must be well below that.

Also if you factor this timing impact, you have the same timing impact on the
denominator, i.e. people who are infected but haven't developped antibodies
yet.

[1] [https://youtu.be/TisDYYWJgBA?t=967](https://youtu.be/TisDYYWJgBA?t=967)

[edit] in fact for the 50%, we have an idea from Cuomo's presentation charts.
The gross daily hostpitalisation rate as of 10-15 days ago was about 2000-2500
per day, and the number of death now is about 500 per day, so that suggests
roughly a 20-25% death rate for hospitalised people (I am sure there must be
some more precise figures somewhere).

~~~
lukeinkster
The death rate of those requiring ventilation in NYC is closer to 88%
[https://jamanetwork.com/journals/jama/fullarticle/2765184](https://jamanetwork.com/journals/jama/fullarticle/2765184)

~~~
tricolon
Outside the context of this virus, for adult men, the survival rate one year
after mechanical ventilation might be 30 percent:
[https://www.ncbi.nlm.nih.gov/pubmed/8404197/](https://www.ncbi.nlm.nih.gov/pubmed/8404197/)

------
TechBro8615
So, at what point can we declare the lockdown to be a harmful overreaction and
start opening countries up? Will we hold anyone accountable for models which
proved to be pessimistic by orders of magnitude, causing implosion of
economies around the world?

~~~
chasd00
has anyone modeled at one point deaths from economic collapse overtake deaths
from Covid19?

~~~
robocat
I would be very sceptical about any models produced in the US, since the issue
is so partisan, and one can tweak variables to prove whatever outcome one
wants from a model.

I think the lost life-years of economic hardship could easily outweigh the
lost life-years of Covid deaths. That is because economic hardship affects
younger people, while Covid deaths primarily affect people with not many years
left to live. But there are many other external costs (social costs if your
grandma dies) and economic benefits to deaths (lower pension payments, home
availability?).

However, given current information, a lockdown for weeks to months seems to
make sense, since the consensus is that economic collapse is not yet immanent,
and that steps can be taken to help keep the economy spinning when lockdown
restrictions start to be relaxed.

~~~
watwut
Economic hardship affects middle aged and old people too.

------
known
But they can infect others

------
cryptonector
At 21% it would be time to end the shutdown.

EDIT: Read the comments below.

~~~
zucker42
That doesn't make sense to me. I would think you'd want to get to the point
where you've reached the carrying capacity, so that "overshoot" of the
equilibrium doesn't result.

~~~
cryptonector
See my other reply below. You can't overshoot 100%, and long before we get
there herd immunity takes hold, and there's no question of the disease being
kept from working its way through -- only a question of managing the rate at
which it does. All in all the economic damage of continued shutdown does not
make sense at this point (at 21% of the population exposed). We should stop
now.

~~~
zucker42
Your comment doesn't address my point. See this Twitter thread,
[https://twitter.com/CT_Bergstrom/status/1251999295231819778](https://twitter.com/CT_Bergstrom/status/1251999295231819778)

specifically this comment:

[https://twitter.com/CT_Bergstrom/status/1252008040376614912](https://twitter.com/CT_Bergstrom/status/1252008040376614912)

for a good illustration of what I'm talking about. Keeping the rate of
transmission low through the peak can definitely save lives.

------
DenisM
This might be a bit blunt but I am not jesting - an article about disease
testing that does not contain the words "false positive" and "false negative"
in some form is literally not worth reading.

Even decent antibodies tests can have 10% false positive rates (bodysphere),
and lots of those tests have dodgy provenance and 20% false positive is not
out of the question.

Here's a better article, thou still not great (paywall):
[https://www.nytimes.com/2020/04/23/nyregion/coronavirus-
anti...](https://www.nytimes.com/2020/04/23/nyregion/coronavirus-antibodies-
test-ny.html)

The closest they come to discussing the errors is to acknowledge there might
be some: _State officials said the test had been calibrated to err on the side
of producing false negatives — to miss some who may have antibodies — rather
than false positives, which would suggest a person had coronavirus antibodies
when they did not._ Not very informative, I know.

A word of caution from the NYC health officials:
[https://www1.nyc.gov/assets/doh/downloads/pdf/han/alert/2020...](https://www1.nyc.gov/assets/doh/downloads/pdf/han/alert/2020/covid-19-status-
of-serologic-testing.pdf)

------
hkai
Aha! So perhaps we shouldn't have shut down the economy and financially ruined
millions of people, not to mention the hundreds of millions of people on the
brink of starvation in developing countries.

Perhaps we just like sharing images of coffins and feeling virtuous.

~~~
SerLava
Even if the study is true, this doesn't follow.

You only get to limit your response if you have the capability to do actual
testing... which we didn't and still largely don't.

------
djrogers
I'm starting to wonder if there aren't 2 (or more) transmission methods for
this virus with differing symptoms. Aerosol transmission with 'I got a cold'
type symptoms, and droplet transmission with 'I got the worst cold I've ever
had' type symptoms.

~~~
grandmczeb
Why would different transmission methods result in different symptoms?

~~~
taeric
Viral load, is what this typically refers to. Akin to an allergic person
seeing one cat versus a room full of them.

And, of course, for some people with allergies, contact where a cat has been
is enough. ;)

So... Complicated.

Edit: was corrected down thread that this is infection dose, not viral load.

~~~
grandmczeb
There’s a very weak association between viral load and symptoms once you’re
infected.

~~~
taeric
But that is what the thread was talking about, right?

Would be nice to see studies. My intuition is that it is weak. But my
intuition doesn't count for much here.

~~~
grandmczeb
Is it? I read the original comment as saying there were significantly
different symptoms based on the transmission method. Even assuming that the
transmission method results in a significantly different viral load, that's
not enough to explain differing symptoms since there's not a whole lot of
observable difference between cases with different severities[1,2]. There are
some studies that show a relationship, but nothing strong enough to explain a
dramatic difference.

If it's true that the transmission method makes a big difference, it's more
likely due to some other reason. E.g. maybe mild strains spread more easily in
the air (although as far as I know there's no evidence that's true.)

[1]
[https://arxiv.org/ftp/arxiv/papers/2003/2003.09320.pdf](https://arxiv.org/ftp/arxiv/papers/2003/2003.09320.pdf)

Page 3. "We did not observe significantly different viral loads in nasal swabs
between symptomatic and asymptomatic."

[2]
[https://www.medrxiv.org/content/10.1101/2020.03.15.20036707v...](https://www.medrxiv.org/content/10.1101/2020.03.15.20036707v2.full.pdf)

Page 4. "There was no obvious difference in viral loads across sex, age groups
and disease severity"

~~~
taeric
Fair. My entry to this thread should have begun with a question mark. I
thought the point of different transmission methods, as frames, was referring
to potential differences in viral load.

~~~
grandmczeb
Rereading your first comment, I think you might be thinking of infection dose.
Viral load is the amount of virus present in a patient. Infection dose is the
amount you're exposed to.

~~~
taeric
So, I was indeed mixing those up. I think most of the following points stand?

~~~
grandmczeb
There's not much evidence that infection dose matters in terms of case
severity either, other than you're just less likely to be infected in the
first place.

------
vkou
If this study is accurate, and is not just working on garbage data, and if
these antibodies actually mean long-term immunity, this means one of two
things:

1\. If the lockdown is lifted, we will see another ~60,000 to 100,000 deaths
in NYC, before it will hit herd immunity.

2\. Or, the lockdown will continue.

The accuracy of antibody studies has been called into doubt, and as far as I
know, nobody has ever followed up on whether or not people with study-detected
antibodies can catch the virus. The data for the latter is unlikely to be
available until the second wave hits.

~~~
DeonPenny
We'd also need to make the decsision to continue a lockdown over a virus with
a 99.5% survival rate or not. Seeing at the flu has a 99.9% survival rate does
it make sense to destroy the economy over that.

~~~
tunesmith
Hospitalization rates per infection are greater for covid than for flu. What
matters is hospital capacity, to protect against greater non-covid death
rates.

~~~
SpicyLemonZest
I agree, but this is not universally believed. Many people argue that hospital
capacity is _not_ what matters, and we must continue lockdowns even if
hospitals won't be overloaded to eradicate the disease.

~~~
DeonPenny
But if that held then we'd eradicate flu and the common cold two. Quarantines
don't eradicate disease they slow the spread but the area under the curve is
constant. I doubt will change the number of infected is a constant regardless
of the rate.

~~~
tunesmith
That's only true if medical and technological advancements don't happen. A
vaccine a year from now means less death if we've locked down in the meantime,
compared to if we haven't locked down. Similarly, if we scale up testing and
contact tracing to the point we can eventually eradicate the disease through
targeted quarantines, a preceding lockdown means less death.

If instead we don't experience any advancements, then right, it just means the
same number of infections are spread out over a longer period of time.

~~~
DeonPenny
Which for me the later seems more possible simply because vaccines from what I
heard would take 5 years. Thinks like SARS and zika still have no vaccine
despite being around for years.

