That was scary

jlarkin@highlandsniptechnology.com wrote in
news:5hnb9f18e884i570foqmvsekaejr5q4rog@4ax.com:

It's had several upgrades, including PicoZed.

And yet their top of the line product is still at 100Mb/s ENET and
USB 2.0 and one core.

 

jlarkin@highlandsniptechnology.com wrote in
news:5hnb9f18e884i570foqmvsekaejr5q4rog@4ax.com:

Where did you see that? It has Gbit ethernet and dual ARM cores and a
gigantic FPGA.

The site you linked. Their top model.

 

[Lasse Langwadt Christense]

tirsdag den 14. april 2020 kl. 18.22.11 UTC+2 skrev jla...@highlandsniptechnology.com:

On Tue, 14 Apr 2020 08:47:21 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

jlarkin@highlandsniptechnology.com wrote in
news47a9ftjatfo34t6q5s6no4h5jrh2e6h41@4ax.com:

On Tue, 14 Apr 2020 10:51:13 +1000, Clifford Heath
no.spam@please.net> wrote:

On 14/4/20 10:34 am, John Larkin wrote:
On Tue, 14 Apr 2020 10:03:18 +1000, Clifford Heath
no.spam@please.net> wrote:

On 14/4/20 5:26 am, John Larkin wrote:
On Mon, 13 Apr 2020 12:13:35 +1000, Clifford Heath
no.spam@please.net> wrote:

On 13/4/20 12:07 pm, jlarkin@highlandsniptechnology.com
wrote:
On Mon, 13 Apr 2020 09:33:14 +1000, Clifford Heath
I should drag out tprof again, it still fills a need that's
substantially un-met by existing tools. It also contained a
dynamic memory profiling mode that was useful.

Sometimes we raise a port pin at the entry of a chunk of
code and drop it at the end, and look at that with an
oscilloscope. A routine can be optimized for worst-case
execution time, which usually matters more than average. A
little thinking can sometimes reduce worst-case by 5:1.

One port pin can be made to blip or change state at several
places in a segment of code. That can look cool on infinite
persistance.

Great way to look at exactly one thing at a time, and quite
unlike what a proper profiler does.

I have histogrammed the program counter. That can be a
revelation. See what's hogging the resources.

That's a trivial profiler, and comes built-in to Linux tools,
always has (since 1976 at least). It tells you nothing about
context switch or interrupt latencies though, because it only
samples during the program's assigned timeslots i.e. while
it's running.

CH

Nobody has guessed about the Linux timeouts I measured. Nobody
has estimated a reasonable IRQ rate for my tiny ARM. An
oscilloscope is good enough for things like that.

Sure! If it works for you, that's great.

On a running Linux system with normal desktop peripherals,
there is a great variety of different kinds of things going on.
In the histogram of latencies, it's very instructive to see the
different spikes for different interrupts (and try to identify
which is which), and to see the variance for each spike.
Kind-of a top-down view, which would augment your bottom-up
one.

CH

We were interested in how long and how often a tight application
loop might be suspended by the OS and drivers and stuff. Would a
profiler tell you that?

Exactly, that's what the histogram is. Put the contents of your
inner loop (or some fixed number of repetitions) in a profiled
function (called from the loop), and the shortest elapsed-time
spike is how long it takes to run if it's not interrupted. All
longer spikes are interrupts or one sort or another. You can see
how long each is, count how many, and see the variability in each
interrupt time (based on the width of the spike).

You do need a CPU with a fine-grained timer you can quickly read,
and you need to ensure that your inner-loop function runs for
significantly longer than the profiler overhead of doing that.

In a Zynq sort of chip, one bailout is to move "code" from the
ARM cpu's into FPGA fabric. I'm often shocked by what people can
implement in VHDL.

I wish I had time and energy to get started with the Zynq, it's
such a nice way of doing things. Someone should do an "Arduino,
but for Zynq".

CH.

It's a MicroZed. We have done several products and a few test sets
with a MicroZed as the compute platform. It has all the power
supplies, DRAM, SD card, Gbit Ethernet, USB, all that done, and
they bring 100 FPGA pins out on connectors. It runs Linux right
out of the box.

https://www.dropbox.com/s/al2x92st7ja7gry/DSC02865.JPG?raw=1

https://www.dropbox.com/s/r6sl0nh8zd9sm7r/ASP_SN1_top.jpg?raw=1

Look like it WOULD be good, if it was not a lame 5 plus year old
design and the punks have not upgraded ANY of it.

It's had several upgrades, including PicoZed.


Way to pricey, only a single GB RAM (how lame) 1 Ethernet of only
100Mb/s. Probably only one ARM core.

Where did you see that? It has Gbit ethernet and dual ARM cores and a
gigantic FPGA. The price is more than reasonable considering what the
Zynq chip and other stuff costs, less than what the parts would cost
us in small quantity. It's in the noise for our aerospace products.

It runs Linux right out of the box if you apply power. The development
software integrates the Linux OS, boot loader, c compiler, and FPGA
compiler. It makes a file with everything, that you copy to an SD card
and plug into the target. Imagine developing all that yourself. It all
worked for us first try.

As usual the linux guy is just yelling about things he doesn't understand

Pretty fuckin lame, actually. There has to be way better than
that.

Design one.

I mean maybe it was a great idea for them years ago, but they needed
to re-invest their profits into upgraded board, not just years of the
some fucking offering.

It's an eval board for the Zynq, not intended to be a profitable
product. It's entirely public and open source, down to the PCB
gerbers. Anybody can build it.

Works for us.

http://www.myirtech.com/list.asp?id=502 has a very similar board for $99

if you buy the chip from digikey it cost $63 ...

 

[Lasse Langwadt Christense]

tirsdag den 14. april 2020 kl. 19.29.09 UTC+2 skrev jla...@highlandsniptechnology.com:

On Tue, 14 Apr 2020 10:12:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:


http://www.myirtech.com/list.asp?id=502 has a very similar board for $99

if you buy the chip from digikey it cost $63 ...


What keeps impressing me is that I can buy boards, especially from
China, all built, for a fraction of what the parts would cost us.

MicroZed is about break-even on parts cost.

their parts cost is very different, if you look at LCSC the price of the Zynq they have in stock is close to 1/3 the price of digikey

 

[Ricky C]

On Tuesday, April 14, 2020 at 6:30:21 AM UTC-4, David Brown wrote:

On 13/04/2020 19:16, Ricky C wrote:
On Monday, April 13, 2020 at 10:25:05 AM UTC-4, David Brown wrote:
On 12/04/2020 21:28, Ricky C wrote:
On Sunday, April 12, 2020 at 12:27:45 PM UTC-4, David Brown wrote:
On 12/04/2020 04:52, Ricky C wrote:

That's your straw man argument. We don't need a vaccine if we
can eliminate the virus. Do they still vaccinate for smallpox?


Smallpox was eliminated by vaccines - so we don't need vaccines for
it /now/.

So you are agreeing with me that if we eliminate the virus we won't
need a vaccine?

Yes - but I am also saying that you need a vaccine to eliminate it. I
don't think it will be practical to do so without a vaccine - it has
spread too far and wide to be contained.

That is the fallacy in your argument. Being spread "far and wide" means nothing. Once this infection is under control and it is eliminated in a given area, it only requires a few things to remain free of the virus. I've already said all that.


Those "few things" would include banning all travel into the virus-free
area. Clearly, that is never going to be practical. The reality will
involve a balance between reducing the risk of the infection
re-occurring in the area, and practicality.

Not "banning" travel, but restricting it and requiring quarantine along with the ever essential contact tracing if the virus does make it in.

But coronavirus? Yeah, it may have leapt from
another animal previously, but there is no indication we are being
reinfected by the same means. Get rid of it in humans and we will be
rid of it forever.

Hopefully, yes.

It is likely that this particular Corona virus was the result of a
mutation or combination from one or more other corona viruses. Whether
that occurred in a human or an animal is unknown. But if it were an
animal and it hasn't spread to other animals, then maybe it is only
significantly infectious in humans and therefore could be eliminated.
(It has been found in some other animals, but only a few, and their
infectiousness is not yet known.)

Ok, so now you are changing your story of the vaccine being essential?


No, I haven't changed my story. The virus might be controllable without
a vaccine, it won't be eliminated without a vaccine. A vaccine alone
might not be enough to eliminate it if the virus survives in animals,
but it could stop it from being an issue for humans.

The only reason the virus won't be eliminated without a vaccine is if there are countries that don't have the will to do what it takes to eliminate it within their borders... like the US.

Not an easy task, but once we get the infection numbers down,
aggressive contact tracing has a lot less impact than the shutdown we
are presently in.


I don't believe it is realistic to get good enough testing and tracking
world-wide in order to eliminate it completely without mass vaccination.
It could certainly be controllable, but not eliminated.

I only care about "controlling" it in this country. I believe that all the more modern countries will contain it and eliminate it within their borders. The other countries will essentially let it "burn out" which will take some time, but after a year or so the infection rates should be so low as to not pose significant threats. Travel bans can be lifted and contact tracing be the only means needed.


Such a myopic "I only care about me and those around me" attitude is the
best guarantee of not getting control of the virus.

It is the only realistic way of dealing with it. The bottom line is you can control your country, but not others. So act accordingly. Thinking you can do anything about the rest of the world is a fantasy.

If you want to avoid the virus re-occurring in the USA (assuming you
first manage to eliminate it there without a vaccine - and that's a big
assumption), you have two choices. Seal off the borders of the USA
permanently with quarantines and comprehensive tests for all
international travel (good luck with your wall), or work towards
eliminating it /everywhere/ throughout the world.

I've already explained why your ideas are draconian, but now you seem to get it. Quarantine, testing and contact tracing. They work. Just ask China.

Obviously the reality will be a compromise and a balance of risks - if
the disease can be eliminated from /most/ of the world, the risks of
travellers spreading it is much smaller, and it can be good enough to
live with. (That is the situation for many serious diseases, such as
Ebola.)

There is not much choice. We don't have a vaccine. So the only solutions are what I'm suggesting.

As for letting it "burn out", what exactly do you mean by that? We now
know that having the virus does not impart full immunity - we don't yet
know how much or how little you get. There are plenty of viruses for
which you get immunity for a year or so, and it flares up on two-year
cycles.

It is typical for such viruses to mutate to less lethal forms. The most effective form of the virus is one that barely makes you sick so it can be transmitted while people continue their normal lives. So the virus has selective pressure for that.

We never developed a treatment or an effective vaccine for the swine flu. It is still with us circulating the globe, yet no one seems to notice.

BTW, where did you read having this virus does not impart full immunity??? I haven't seen that. So far everyone is saying they don't know.

Maybe this will all be controllable and containable. Maybe better
control on travelling, better hygiene habits, permanent contact tracing
of populations, etc., will mean that as we see new outbreaks around the
world, there won't be much of it spreading in the USA. There are a lot
of unknown variables here - a lot of maybes. I am fairly confident that
a reasonable balance will be established in time.

But a good vaccine would make all the difference.

I believe the expected date is 2021 or 2022.

(This is my estimation and extrapolation, rather than a known fact.)

Remember, recovery from Covid-19 does not appear to give very good
immunity - so all you need is a few pockets of it hidden away somewhere,
and the potential for new outbreaks will be there.

(One can hope that they would be caught and isolated faster now, of course.)

Where did you see any indication that the disease does not leave the person immune? I have not seen that at all.


This is a crucial point. I think you'd agree with me more above if you
understood this.

For some diseases, after recovery you have long-term immunity with
antibodies. For other diseases, the immunity is short-term or only
partial. It is a common assumption - but often incorrect - that if
you've had a disease, you are immune for life (given a consistent
pathogen - flu's and colds are caused by lots of related viruses). It
is this assumption that led to the "everyone's going to get it sooner or
later - let people get it and build up a herd immunity" strategy used by
some countries.

The assumption is no more than that - an assumption. It often does not
apply.

And it does not /seem/ to apply for Covid-19.

The studies are early as yet - we'll need many more, and it's impossible
to evaluate long-term immunity without waiting a long time. But
preliminary testing is showing unexpectedly low anti-body counts in a
sizeable fraction of people who have recovered from the disease.

We don't yet know how this will work out. Maybe people will have enough
immunity that re-infections will be mild or symptomless. Maybe new
infections will boost the immune response to give a longer term immunity
after the second round. But maybe re-infections will leave people with
mild (or different) symptoms but still infectious.


https://time.com/5810454/coronavirus-immunity-reinfection/
http://www.koreaherald.com/view.php?ud=20200412000213&np=3&mp=1
https://www.telegraph.co.uk/science/2020/04/08/coronavirus-immunity-test-faces-setback-recovered-patients-present/
https://abcnews.go.com/Health/questions-remain-covid-19-recovery-guarantee-immunity-reinfection/story?id=70085581

You seem to be coming down on the side of not gaining immunity from this virus when the jury is still out...

Two links are of the same Korean report of 111 people who tested positive after having the virus and testing negative.

"Health authorities here have said the virus was highly likely to have been reactivated, instead of the people being reinfected, as they tested positive again in a relatively short time after being released from quarantine."

The other two links are about an not peer reviewed study finding "low" levels of antibodies in previously infected individuals with zero clinical indication of reinfection. That is doubly lame.

Add to this mixture the risk of the virus mutating - the more people
that get it, and the more time that goes past with wide-scale infection,
the bigger the chance of it mutating to something that will then infect
people anew.

Mutation is most likely a good thing. It is much less likely the virus will widely mutate the antigens that produce the immune response since there is currently very little selection pressure for that with relatively small proportions of the population infected. Mutating the impact of infection is much more likely since those who show symptoms are quickly isolated and pass on the infection much less often. Combine that will social distancing and the more virulent forms see a higher selective pressure than less virulent forms.

Measles was almost eliminated by vaccines, but there so many
"anti-vaxer" morons that the elimination failed, and there are
still outbreaks - so kids still need the vaccines. The same
applies to polio.

Covid-19 can, hopefully, be eliminated by vaccines. Whether it
will or not is another matter - but good vaccines will certainly
prevent it being a problem.

But can Covid-19 be eliminated /without/ a vaccine? I don't think
so. It is far too wide-spread for that. It can be kept at bay by
other measures, and some places can be kept free of it, but if
there is freedom of movement, outbreaks will always return.

Wide spread is not the issue. The shutdown will allow us to get the
numbers to a point that contact tracing can confine the disease.

If South Korea can do it, why can't we?


Because you are only one country. To eliminate the virus anywhere, it
needs to be eliminated /everywhere/. Maybe the USA can do the kind of
tracking that South Korea managed (I doubt it - Americans are not as
obedient. Freedom works both ways). But you won't get that same
tracking across India, Africa, war-torn Syria, Afghanistan, etc.

Ah, you are arguing semantics. Ok, fine. I'm talking about eliminating it in various countries that are capable. The rest of the world will deal with it for a while longer and have many more deaths, but even there this disease will pass once it infects enough people.


I won't say I am "arguing semantics", but the different terms and
viewpoints does at least partly explain why we appear to have different
opinions here.


Another aspect that is not yet understood is the long-term effects on
people that have had serious symptoms but recovered. Preliminary
indications are that it can involve not just lung damage, but damage to
the heart and liver (and this is not just for people who needed
ventilators).

Yep, that is not at all uncommon that a disease has subtle effects on patients that remain even after being cured.

I suppose it could mutate and become infectious again after passing through the lion's share of the world community. But technically that is a new disease and a vaccine won't protect from that either. Perhaps they will crack the code on developing a vaccine to a slowly evolving antigen on the virus, but we've not been able to do that with the cold or flu.

Even vaccines are no match for an evolving virus.


That depends on how the vaccine works (there are many paths to a
vaccine, and many are being researched concurrently for Covid-19).
Vaccines often target particular proteins on the virus shell - if a
mutation does not change that protein, the vaccine still works. It is
not uncommon that a vaccine can be of some benefit to a related or
mutated virus even if it is not a perfect match (that happens when the
estimates of yearly flu variants are not accurate). And for some
vaccine types, they can be made in a flexible and adaptable way - like
the flu vaccines, that can be adapted for different mutations in a few
months.

Vaccines are not perfect (especially when we don't have one), but they
are the best tool we have against viruses.

You seem to be walking down both sides of the street. Mutations are random and frequent in viruses. It is then up to selective pressure to spread a mutation through the population if it "improves" the virus, meaning more likely to reproduce. As I've already indicated there is little selective pressure to promote mutations involving resistance to a vaccine we don't yet have. If the virus infection rate is low when we develop and use the vaccine there is less opportunity for it to mutate. Working to eliminate the virus from each country is a win-win. Lower infection rates = fewer deaths and less opportunity for the virus to mutate once we have a vaccine.

--

Rick C.

-+-+ Get 1,000 miles of free Supercharging
-+-+ Tesla referral code - https://ts.la/richard11209

 

[whit3rd]

On Tuesday, April 14, 2020 at 1:20:07 PM UTC-7, Ricky C wrote:

On Tuesday, April 14, 2020 at 6:30:21 AM UTC-4, David Brown wrote:

Such a myopic "I only care about me and those around me" attitude is the
best guarantee of not getting control of the virus.

It is the only realistic way of dealing with it. The bottom line is you can control your country, but not others.

Alas, no. It's a global problem, and requires global solution. The
local approach is correct for your local authority (leaders of country A cannot order leaders
of country B) but is incorrect for an international (UN? WHO?) coordinated effort.

A satisfactory outcome requires international coordination, if only on air-travel
logistics.

 

[Ricky C]

On Tuesday, April 14, 2020 at 8:31:45 PM UTC-4, whit3rd wrote:

On Tuesday, April 14, 2020 at 1:20:07 PM UTC-7, Ricky C wrote:
On Tuesday, April 14, 2020 at 6:30:21 AM UTC-4, David Brown wrote:

Such a myopic "I only care about me and those around me" attitude is the
best guarantee of not getting control of the virus.

It is the only realistic way of dealing with it. The bottom line is you can control your country, but not others.

Alas, no. It's a global problem, and requires global solution. The
local approach is correct for your local authority (leaders of country A cannot order leaders
of country B) but is incorrect for an international (UN? WHO?) coordinated effort.

A satisfactory outcome requires international coordination, if only on air-travel
logistics.

So what will you have third world countries do where the full population don't even have access to running water or other means of sanitation???

As already stated, the virus is not likely to be eliminated from the planet. So the alternative is to make your country safe.

Coordinate all you like, but fend for yourself.

Bottom line is there are no international actions. Only the actions of countries.

--

Rick C.

-++- Get 1,000 miles of free Supercharging
-++- Tesla referral code - https://ts.la/richard11209

 

[whit3rd]

On Tuesday, April 14, 2020 at 5:54:35 PM UTC-7, Ricky C wrote:

On Tuesday, April 14, 2020 at 8:31:45 PM UTC-4, whit3rd wrote:

... a global problem, and requires global solution. The
local approach is correct for your local authority (leaders of country A cannot order leaders
of country B) but is incorrect for an international (UN? WHO?) coordinated effort.

A satisfactory outcome requires international coordination, if only on air-travel
logistics.

So what will you have third world countries do where the full population don't even have access to running water or other means of sanitation???

Send in a mobile team to set up vaccination centers? Sanitation in sparse population areas isn't
really involved, but local market centers ought to have a priority on preventive care.

> As already stated, the virus is not likely to be eliminated from the planet. So the alternative is to make your country safe.

Not really an 'alternative' that can work. We don't have lots of nations on this planet that
have all their resources and products produced and consumed locally; even Rome had to
trade with Wales to get their tin. Nations don't entirely stand alone, they shop abroad.

Even just cutting off ONE neighboring country can be damaging; ask Cuba how they liked the
embargo.

 

[Ricky C]

On Wednesday, April 15, 2020 at 2:00:05 AM UTC-4, whit3rd wrote:

On Tuesday, April 14, 2020 at 5:54:35 PM UTC-7, Ricky C wrote:
On Tuesday, April 14, 2020 at 8:31:45 PM UTC-4, whit3rd wrote:

... a global problem, and requires global solution. The
local approach is correct for your local authority (leaders of country A cannot order leaders
of country B) but is incorrect for an international (UN? WHO?) coordinated effort.

A satisfactory outcome requires international coordination, if only on air-travel
logistics.

So what will you have third world countries do where the full population don't even have access to running water or other means of sanitation???

Send in a mobile team to set up vaccination centers? Sanitation in sparse population areas isn't
really involved, but local market centers ought to have a priority on preventive care.

We seem to be on different pages. How do you vaccinate against SARS-CoV-2 if there is no vaccine??? What is there to coordinate other than travel restrictions and sharing medication and information?

Of course sanitation is essential. You seem to forget that a very important part of reducing the spread of this disease is hand washing... proper hygiene.

As already stated, the virus is not likely to be eliminated from the planet. So the alternative is to make your country safe.

Not really an 'alternative' that can work. We don't have lots of nations on this planet that
have all their resources and products produced and consumed locally; even Rome had to
trade with Wales to get their tin. Nations don't entirely stand alone, they shop abroad.

I almost think you are just trying to play dumb. No one said trade had to stop. Goods can be disinfected by sitting for 72 hours. Most shipments take that long to arrive.

Even just cutting off ONE neighboring country can be damaging; ask Cuba how they liked the
embargo.

Please just stop being disingenuous.

Make America Safe Again!

--

Rick C.

-+++ Get 1,000 miles of free Supercharging
-+++ Tesla referral code - https://ts.la/richard11209

 

[Martin Brown]

On 12/04/2020 17:32, jlarkin@highlandsniptechnology.com wrote:

On Sun, 12 Apr 2020 09:39:02 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 10/04/2020 18:01, jlarkin@highlandsniptechnology.com wrote:
On Fri, 10 Apr 2020 16:46:23 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 10/04/2020 16:06, jlarkin@highlandsniptechnology.com wrote:

Test density is increasing exponentially but case rates are not
adjusted. My guesses are as good as anybody else' now.

No. You are woefully ignorant and *very* determined to remain so.

The German health system has run an antibody test in one of the hottest
spots on the planet and found that only 14% of the population has
actually got antibodies to the virus at present.

https://www.technologyreview.com/2020/04/09/999015/blood-tests-show-15-of-people-are-now-immune-to-covid-19-in-one-town-in-germany/

That's a useful bit of data. Prefacing it with "willfully ignorant"
isn't. I didn't deliberately avoid seeing the German data.

You cherry pick data to suit your argument so often that it is difficult
to tell whether you are unaware of the scientific data or deliberately
refusing to look at it. You are a science denier at heart.

I consider a lot of data and speculate about possible dynamics. That
is not an "argument." I could make an argument, but I haven't. I'd
probably wind up being wrong. I hate to be wrong, because it suggests
a lapse of good thinking.

You have been claiming that it would all be fine and there was nothing
to worry about for ages.

That's the way some people design electronics: consider as many
outrageous possibilities as you can, and analyze the consequences of
each. Considering unsanctioned alternatives offends most people.

"Science teaches us to doubt." Or should.

There is a difference between doubting something and going round with
your eyes shut and fingers in your ears impervious to all new data.

I have said for some time that we need general-population antibody
studies to understand the dynamics. The usual response was to ridicule
me for suggesting that antibody studies would be worthwhile. Now you
ridicule me because an antibody study has been done. Please explain
that.

I have never ridiculed you over needing more testing. More testing in
the population is the only way we will get back control before a vaccine
is available (and that is likely to be some long way off yet).

I think active-infection testing is over-rated and abused, another
press mania like ventilators. It has to be done repeatedly on everyone
every week or two to be effective. If we had an antibody test, we
could let known-immune people back to work. I wonder what the number
will be. The 14% is at least a hint.

UK seem to guestimate that the present infection rate in cities is
around the 1-2% level. This is just about plausible since it is now
rampant in care homes for the elderly and there is little that can be
done to stop it. The first local case I know of that wasn't caught in
London is an elderly person with a home care package.

The next thing to estimate is what fraction of the population would
catch it if exposed. The current opinion is that "no-one has natural
immunity to coronavirus" but there are counter-cases.

There is no reason to suppose that anyone is immune to such a new
zoonotic virus. 80% apparently show no symptoms but become infective
carriers - that is what makes the thing so effective at community
transmission and why social distancing is so important now.

On cruise and military ships, about as bad as a transmission
environment as you could get, only a fraction of the population got
infected.

That is because once they realised what was happening they locked down
tight to control the infection. Cruise ships are all too used to the
highly infectious norovirus winter vomiting bug wreaking havoc.

If 25% can get
it and 14% have had it, R0 is down about half. So it may peak and
decline soon, as it seems to have done in many places, especially in
europe. Austria and Luxembourg are nice tight test cases. Australia
had a nice bell peak of new cases a couple of weeks ago, with a total
of about 6K confirmed cases so far.

If that were true then it might back off once 60% of the people who are
susceptible to catching it have had it and recovered. But the evidence
from the very rapid exponential growth phase is that any such effect has
to be modest. The unchecked exponential growth before lockdown was
textbook pure A^t into a virgin entirely susceptible population.

Or R was very high among a minority of the population.

Although it is a possibility there doesn't seem to be much evidence that
it discriminates like that at all. It certainly seems to have much worse
consequences for a specific subset of the population.

Once the proportion of people becomes more than a third of the reservoir
you should see a clear deviation from exponential even in noisy data.

In the graphs I've seen of most countries, exponential growth became
linear very early in the infection, when far less than a third had
been officially counted as cases. Even in countries that were not
locked down. Nothing grows exponentially forever. No country or ship
or nursing home has ever hit 1/3.

It has become linear because of the near total lockdown. It was growing
exponentially at an alarming rate until then. The number of fatalities
in the UK is presently roughly constant around 750-800. The new cases
figure is expected to tail off now that we are three weeks into
lockdown. A worrying number of medics are getting seriously ill with it.

The Hopkins site shows that there have been 526K confirmed cases in
the USA, out of a population of 300 million, and the new case curve is
flat. Looks to me like the peak is about now.

That is probably over optimistic. The only thing keeping it suppressed
at the moment is the hard lockdown and social distancing. Relax those
constraints and it will return again to exponential growth.

There seems to be some evidence now that the virus is worse for people
who do not have a few percent of Neanderthal DNA in their genome. The
extra risk factor for them being almost as bad as that for being male.

Surely we evolve to resist viruses as they evolve to attack us.

Not much scope for that when the virus predominantly kills older people.

People who survive the infection will hopefully be immune for life.

I do predict a massive surplus of cheap never-used ventilators.

So do I. The Dyson ones will be incredibly stylish and ten times the
price of any other model if their usual MO applies. Or incredibly noisy
and totally ineffective if their hand drier team get the gig.

Some MDs say that ventilators net damage people. They suggest
"proning", namely flipping patients over, to lie on their stomach
instead of their back. Seems to help. Reduces snoring too, another
great benefit to public health and domestic tranquility.

I think that is in combination with positive pressure face mask oxygen
intervention or ventilation. Seems that more good lung area is available
if the patient is face down.

Even with loads of ventilators they are now in real danger running out
of the anaesthetic needed to sedate the patients hooked up to them. It
is easy to build extra physical hospital beds but hard to find all the
skilled staff needed to operate them (not least because PPE flaws seem
to result in medics getting ill themselves and all too often dying).

The UK has purchased an antibody test that appears not to work well
enough to be remotely useful in the field (and are presently trying to
get their money back). Wired has dissected the problem quite well:

https://www.wired.co.uk/article/coronavirus-antibody-tests-uk-accuracy


There seems to be a lot of hostility to antibody testing.

Partly because at the moment it may not be reliable enough to be
worthwhile. That is the problem that the UK seems to have hit.

A test with false positives that incorrectly tells 5% of the population
they are immune when they are still at risk is not particularly useful.

OTOH it if does detect almost all genuine cases of having had the
infection you can still use it to gain some insight into the progress of
the infection even if you have to correct for the false positive bias.

I am not sure I entirely agree with their current favourite soundbite
that "a bad test is worse than no test at all". Even with its known
systematic errors a test that is 90% good and 10% bad still gives you
some useful information but it needs much more careful interpretation.

If we are managing based on statistical benefit, an antibody test that
is 95% accurate would be very useful. We could put tested-positive
people back to work. Each false-positive-immune person would be
working around 19 truly immune people.

An interesting point that I hadn't considered. We can put a clear bound
on the false positive rate of the test used in Germany and it is still
good enough to ensure herd immunity in those it gives the green light.

That isn't good enough for front line staff who may be Covid-19 patient
facing but it is fine for deciding if people can go back to normal work.

One new line of attack that is interesting is that they are presently
running supercomputer pattern matching against the UK Biobank and
Icelandic full genomic sequence data cross correlated with severity of
illness in those that have caught the disease.

The intention is to identify the 80% that will be asymptomatic and/or
the 1% who are most likely to be in very serious trouble. That is
another possible way out of lockdown but it is right at the limits of
computing power to search for the proverbial needle in a haystack.

https://www.bbc.co.uk/news/health-52243605
https://www.ukbiobank.ac.uk/2020/04/covid/

--
Regards,
Martin Brown

 

[Ricky C]

On Wednesday, April 15, 2020 at 3:47:37 AM UTC-4, Martin Brown wrote:

On 12/04/2020 17:32, jlarkin@highlandsniptechnology.com wrote:
On Sun, 12 Apr 2020 09:39:02 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 10/04/2020 18:01, jlarkin@highlandsniptechnology.com wrote:
On Fri, 10 Apr 2020 16:46:23 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 10/04/2020 16:06, jlarkin@highlandsniptechnology.com wrote:

Test density is increasing exponentially but case rates are not
adjusted. My guesses are as good as anybody else' now.

No. You are woefully ignorant and *very* determined to remain so.

The German health system has run an antibody test in one of the hottest
spots on the planet and found that only 14% of the population has
actually got antibodies to the virus at present.

https://www.technologyreview.com/2020/04/09/999015/blood-tests-show-15-of-people-are-now-immune-to-covid-19-in-one-town-in-germany/

That's a useful bit of data. Prefacing it with "willfully ignorant"
isn't. I didn't deliberately avoid seeing the German data.

You cherry pick data to suit your argument so often that it is difficult
to tell whether you are unaware of the scientific data or deliberately
refusing to look at it. You are a science denier at heart.

I consider a lot of data and speculate about possible dynamics. That
is not an "argument." I could make an argument, but I haven't. I'd
probably wind up being wrong. I hate to be wrong, because it suggests
a lapse of good thinking.

You have been claiming that it would all be fine and there was nothing
to worry about for ages.

Not really. He does the Trump thing where he never actually says ANYTHING. He just talks about stuff in ways that makes you think he has said something. Limbaugh does the same thing. Lots of incomplete sentences and the sentences that are complete are about half thoughts.

For example... he never said the virus was not on an exponential growth curve. Without saying ANYTHING about why, he pointed out that eventually all exponential growth comes to an end. Yes, he's right. But the reason to point out the exponential growth was to show what would happen if we did nothing to curb this disease.

In reality, on issues like this, in many ways Larkin is a troll, casting out partial truths and irrelevant facts just to get someone to take the bait and argue against him. Then he complains that people won't simply discuss the facts which he has not been doing the whole time.

That's the way some people design electronics: consider as many
outrageous possibilities as you can, and analyze the consequences of
each. Considering unsanctioned alternatives offends most people.

"Science teaches us to doubt." Or should.

There is a difference between doubting something and going round with
your eyes shut and fingers in your ears impervious to all new data.

I would think anyone who has been here very long would know Larkin is very good at deciding what fits his world model and then justifying it with the cherry picked data he chooses to believe.

I have said for some time that we need general-population antibody
studies to understand the dynamics. The usual response was to ridicule
me for suggesting that antibody studies would be worthwhile. Now you
ridicule me because an antibody study has been done. Please explain
that.

I have never ridiculed you over needing more testing. More testing in
the population is the only way we will get back control before a vaccine
is available (and that is likely to be some long way off yet).

I think active-infection testing is over-rated and abused, another
press mania like ventilators. It has to be done repeatedly on everyone
every week or two to be effective. If we had an antibody test, we
could let known-immune people back to work. I wonder what the number
will be. The 14% is at least a hint.

UK seem to guestimate that the present infection rate in cities is
around the 1-2% level. This is just about plausible since it is now
rampant in care homes for the elderly and there is little that can be
done to stop it. The first local case I know of that wasn't caught in
London is an elderly person with a home care package.

I can assure you there are things that can be done, but they are serious and require a lot testing, contact tracing and isolating the care givers from the general population. But since we should all be in a lockdown situation the isolation part should not be a big deal.

The retirement community I am familiar with has put everyone in virtual lock down. No visitors and even no contact with the staff that isn't essential. My fiend is 93 and blind (mostly) but lives alone. He used to go to the dining room for lunch, now they bring it to his door and leave it on the table outside for him to pick up. They are trying, but they don't require people to stay at home and I believe they have had a small number of illnesses.

The next thing to estimate is what fraction of the population would
catch it if exposed. The current opinion is that "no-one has natural
immunity to coronavirus" but there are counter-cases.

There is no reason to suppose that anyone is immune to such a new
zoonotic virus. 80% apparently show no symptoms but become infective
carriers - that is what makes the thing so effective at community
transmission and why social distancing is so important now.

On cruise and military ships, about as bad as a transmission
environment as you could get, only a fraction of the population got
infected.

That is because once they realised what was happening they locked down
tight to control the infection. Cruise ships are all too used to the
highly infectious norovirus winter vomiting bug wreaking havoc.

If 25% can get
it and 14% have had it, R0 is down about half. So it may peak and
decline soon, as it seems to have done in many places, especially in
europe. Austria and Luxembourg are nice tight test cases. Australia
had a nice bell peak of new cases a couple of weeks ago, with a total
of about 6K confirmed cases so far.

If that were true then it might back off once 60% of the people who are
susceptible to catching it have had it and recovered. But the evidence
from the very rapid exponential growth phase is that any such effect has
to be modest. The unchecked exponential growth before lockdown was
textbook pure A^t into a virgin entirely susceptible population.

Or R was very high among a minority of the population.

Although it is a possibility there doesn't seem to be much evidence that
it discriminates like that at all. It certainly seems to have much worse
consequences for a specific subset of the population.

Larkin is obsessed with alternative explanations for the data in spite of the simple and obvious one being what everyone says, the virus grew exponentially until we modified our behavior giving it less opportunity to spread. It is still spreading widely at high rates, but the rate of spreading isn't growing exponentially anymore.

Why do you think he can't accept this simple explanation? He seems to feel that because we weren't testing adequately early on, the curve must be due entirely to the growth in testing rather than a combination of the two.

Once the proportion of people becomes more than a third of the reservoir
you should see a clear deviation from exponential even in noisy data.

In the graphs I've seen of most countries, exponential growth became
linear very early in the infection, when far less than a third had
been officially counted as cases. Even in countries that were not
locked down. Nothing grows exponentially forever. No country or ship
or nursing home has ever hit 1/3.

It has become linear because of the near total lockdown. It was growing
exponentially at an alarming rate until then. The number of fatalities
in the UK is presently roughly constant around 750-800. The new cases
figure is expected to tail off now that we are three weeks into
lockdown. A worrying number of medics are getting seriously ill with it.

In reality, if you have been in lockdown for two weeks, the rate of new infections should be dropping like a stone. If the new infection rate has only leveled off that means your lockdown is not good enough. That's what's happening here in the US. We don't even have a lockdown in some of the US. I haven't seen independent graphs for our states, but I'd like to so I can see which are still growing and which are leveling off.

The Hopkins site shows that there have been 526K confirmed cases in
the USA, out of a population of 300 million, and the new case curve is
flat. Looks to me like the peak is about now.

That is probably over optimistic. The only thing keeping it suppressed
at the moment is the hard lockdown and social distancing. Relax those
constraints and it will return again to exponential growth.

Or course a reasonable person can see that. Larkin wants to believe the virus has an expiration date and is not capable of infecting a large portion of the country. Why do you think that is?

There seems to be some evidence now that the virus is worse for people
who do not have a few percent of Neanderthal DNA in their genome. The
extra risk factor for them being almost as bad as that for being male.

Surely we evolve to resist viruses as they evolve to attack us.

Not much scope for that when the virus predominantly kills older people.

People who survive the infection will hopefully be immune for life.

Immunity falls with time for nearly every disease. Same with many vaccines, that's why we need repeated shots.

I do predict a massive surplus of cheap never-used ventilators.

So do I. The Dyson ones will be incredibly stylish and ten times the
price of any other model if their usual MO applies. Or incredibly noisy
and totally ineffective if their hand drier team get the gig.

Some MDs say that ventilators net damage people. They suggest
"proning", namely flipping patients over, to lie on their stomach
instead of their back. Seems to help. Reduces snoring too, another
great benefit to public health and domestic tranquility.

I think that is in combination with positive pressure face mask oxygen
intervention or ventilation. Seems that more good lung area is available
if the patient is face down.


Even with loads of ventilators they are now in real danger running out
of the anaesthetic needed to sedate the patients hooked up to them. It
is easy to build extra physical hospital beds but hard to find all the
skilled staff needed to operate them (not least because PPE flaws seem
to result in medics getting ill themselves and all too often dying).

The UK has purchased an antibody test that appears not to work well
enough to be remotely useful in the field (and are presently trying to
get their money back). Wired has dissected the problem quite well:

https://www.wired.co.uk/article/coronavirus-antibody-tests-uk-accuracy


There seems to be a lot of hostility to antibody testing.

Partly because at the moment it may not be reliable enough to be
worthwhile. That is the problem that the UK seems to have hit.

A test with false positives that incorrectly tells 5% of the population
they are immune when they are still at risk is not particularly useful..

OTOH it if does detect almost all genuine cases of having had the
infection you can still use it to gain some insight into the progress of
the infection even if you have to correct for the false positive bias.

I am not sure I entirely agree with their current favourite soundbite
that "a bad test is worse than no test at all". Even with its known
systematic errors a test that is 90% good and 10% bad still gives you
some useful information but it needs much more careful interpretation.

If we are managing based on statistical benefit, an antibody test that
is 95% accurate would be very useful. We could put tested-positive
people back to work. Each false-positive-immune person would be
working around 19 truly immune people.

An interesting point that I hadn't considered. We can put a clear bound
on the false positive rate of the test used in Germany and it is still
good enough to ensure herd immunity in those it gives the green light.

That isn't good enough for front line staff who may be Covid-19 patient
facing but it is fine for deciding if people can go back to normal work.

One new line of attack that is interesting is that they are presently
running supercomputer pattern matching against the UK Biobank and
Icelandic full genomic sequence data cross correlated with severity of
illness in those that have caught the disease.

The intention is to identify the 80% that will be asymptomatic and/or
the 1% who are most likely to be in very serious trouble. That is
another possible way out of lockdown but it is right at the limits of
computing power to search for the proverbial needle in a haystack.

https://www.bbc.co.uk/news/health-52243605
https://www.ukbiobank.ac.uk/2020/04/covid/

So will these super computers tell us how to build the computer to give us the question? No, wait, that was something else.

I wonder if they use any of the truly supercomputers being used these days?

--

Rick C.

+--- Get 1,000 miles of free Supercharging
+--- Tesla referral code - https://ts.la/richard11209

 

[David Brown]

On 14/04/2020 22:20, Ricky C wrote:

On Tuesday, April 14, 2020 at 6:30:21 AM UTC-4, David Brown wrote:
On 13/04/2020 19:16, Ricky C wrote:
On Monday, April 13, 2020 at 10:25:05 AM UTC-4, David Brown
wrote:
On 12/04/2020 21:28, Ricky C wrote:
On Sunday, April 12, 2020 at 12:27:45 PM UTC-4, David Brown
wrote:
On 12/04/2020 04:52, Ricky C wrote:

<snip>

Those "few things" would include banning all travel into the
virus-free area. Clearly, that is never going to be practical.
The reality will involve a balance between reducing the risk of the
infection re-occurring in the area, and practicality.

Not "banning" travel, but restricting it and requiring quarantine
along with the ever essential contact tracing if the virus does make
it in.

Even if tests can get good enough that quarantine can be reduced to a
few days, it would be massively intrusive. (And tests are currently
/not/ good enough - we have top-range RNA tests in Norway, and they have
false negatives as well as false positives. We can hope for better
tests, but at least one false positive case appears to be due to the
virus being in the person's lower lungs but not upper airway.)

Contact tracing depends on voluntary cooperation. Will that be good
enough? Maybe - it depends on the level of risk you are willing to accept.

Such a myopic "I only care about me and those around me" attitude
is the best guarantee of not getting control of the virus.

It is the only realistic way of dealing with it. The bottom line is
you can control your country, but not others. So act accordingly.
Thinking you can do anything about the rest of the world is a
fantasy.

Helping other countries is entirely possible - and the weaker, poorer
and less stable countries of the world won't have a chance of
eliminating the virus (with or without vaccines) without help. You are
right that you can't /control/ other countries, but you /can/ help them.

If you want to avoid the virus re-occurring in the USA (assuming
you first manage to eliminate it there without a vaccine - and
that's a big assumption), you have two choices. Seal off the
borders of the USA permanently with quarantines and comprehensive
tests for all international travel (good luck with your wall), or
work towards eliminating it /everywhere/ throughout the world.

I've already explained why your ideas are draconian, but now you seem
to get it. Quarantine, testing and contact tracing. They work.
Just ask China.

Parts of China are still on lockdown, and movement into the country is
highly restricted.

I agree that you can come a long way without a vaccine - if your country
is willing and able to take the necessary steps, and especially if it
starts soon enough (a bit late for that now in the USA).

But without a vaccine - without /knowing/ that the virus is not found
elsewhere, and so will not turn up in your own country - you will always
be on alert, suspicious of travellers and foreigners, monitored and
tracked, and restricted in your way of life.

Obviously the reality will be a compromise and a balance of risks -
if the disease can be eliminated from /most/ of the world, the
risks of travellers spreading it is much smaller, and it can be
good enough to live with. (That is the situation for many serious
diseases, such as Ebola.)

There is not much choice. We don't have a vaccine. So the only
solutions are what I'm suggesting.

Currently, yes, absolutely.

As for letting it "burn out", what exactly do you mean by that? We
now know that having the virus does not impart full immunity - we
don't yet know how much or how little you get. There are plenty of
viruses for which you get immunity for a year or so, and it flares
up on two-year cycles.

It is typical for such viruses to mutate to less lethal forms. The
most effective form of the virus is one that barely makes you sick so
it can be transmitted while people continue their normal lives. So
the virus has selective pressure for that.

Over the long term in a natural environment, that is correct - viruses
and their hosts evolve together to form a stable bias. In the shorter
term, there are no biases - mutations are random. (That does not mean
there are equal chances of a new variant being more or less harmful -
merely that we need to think of the short-term potentials as well as
what will happen over the next few hundred thousand years.)

We never developed a treatment or an effective vaccine for the swine
flu. It is still with us circulating the globe, yet no one seems to
notice.

There /was/ a reasonably effective vaccine against swine flu in 2009,
and it was widely used - like most people in this country, I've had it.
It greatly reduced the spread of the virus.

No one is particularly concerned about swine flu because it is very mild
- significantly less virulent than normal seasonal flu, though more
infectious. And a fair proportion of people have a natural immunity,
due to its similarities to other flu viruses. The prime concerns during
that pandemic were the disruption to economies from many people getting
ill at once (in bed for a week ill, not hospitalised ill), and the risk
of it mutating.

BTW, where did you read having this virus does not impart full
immunity??? I haven't seen that. So far everyone is saying they
don't know.

Mostly it is still a case of "we don't know". But there have been
follow-up tests (mostly in China and South Korea so far, since they had
earlier cases) of people who have had the virus and recovered, and in
about 30% of the people they found little or no antibodies. That is
just weeks after recovery. People have also been found to have been
infected again, after having recovered. (I gave some links earlier, but
I'm sure you can find some English-language Korean articles, or reports
in English-language journals or newspapers that you trust. I have
certainly seen them in Norwegian sources.)

It is clearly too early to be sure of anything here. The numbers tested
were small, there hasn't been a long time passed since people have been
recovering, and most countries are concentrating on dealing with sick
people rather than testing recovered people.

What we /do/ know is that there are strong indications that immunity
will be partial, incomplete and limited.

(Immunity from past diseases is almost always limited - good enough to
make your chances of reinfection small, but not nearly as complete and
lasting as commonly thought.)

Maybe this will all be controllable and containable. Maybe better
control on travelling, better hygiene habits, permanent contact
tracing of populations, etc., will mean that as we see new
outbreaks around the world, there won't be much of it spreading in
the USA. There are a lot of unknown variables here - a lot of
maybes. I am fairly confident that a reasonable balance will be
established in time.

But a good vaccine would make all the difference.

I believe the expected date is 2021 or 2022.

Dates are a bit of a guesswork here - it will be ready when it's ready.
But those are the estimates, yes. If we keep funding vaccine
development and work in parallel on the various possible strategies, we
maximise the chance that at least one of them will work well.

Bill Gates has the right idea. (He made his fortune through theft, cons
and crime, but he is doing a lot of good with the money now.) The Gates
Foundation is paying towards building vaccine factories before we know
which ones will work, to minimise the time to production.

<https://www.weforum.org/agenda/2020/04/bill-gates-7-potential-coronavirus-vaccines/>

(This is my estimation and extrapolation, rather than a known
fact.)

Remember, recovery from Covid-19 does not appear to give very
good immunity - so all you need is a few pockets of it hidden
away somewhere, and the potential for new outbreaks will be
there.

(One can hope that they would be caught and isolated faster
now, of course.)

Where did you see any indication that the disease does not leave
the person immune? I have not seen that at all.


This is a crucial point. I think you'd agree with me more above if
you understood this.

For some diseases, after recovery you have long-term immunity with
antibodies. For other diseases, the immunity is short-term or
only partial. It is a common assumption - but often incorrect -
that if you've had a disease, you are immune for life (given a
consistent pathogen - flu's and colds are caused by lots of related
viruses). It is this assumption that led to the "everyone's going
to get it sooner or later - let people get it and build up a herd
immunity" strategy used by some countries.

The assumption is no more than that - an assumption. It often does
not apply.

And it does not /seem/ to apply for Covid-19.

The studies are early as yet - we'll need many more, and it's
impossible to evaluate long-term immunity without waiting a long
time. But preliminary testing is showing unexpectedly low
anti-body counts in a sizeable fraction of people who have
recovered from the disease.

We don't yet know how this will work out. Maybe people will have
enough immunity that re-infections will be mild or symptomless.
Maybe new infections will boost the immune response to give a
longer term immunity after the second round. But maybe
re-infections will leave people with mild (or different) symptoms
but still infectious.


https://time.com/5810454/coronavirus-immunity-reinfection/
http://www.koreaherald.com/view.php?ud=20200412000213&np=3&mp=1
https://www.telegraph.co.uk/science/2020/04/08/coronavirus-immunity-test-faces-setback-recovered-patients-present/


https://abcnews.go.com/Health/questions-remain-covid-19-recovery-guarantee-immunity-reinfection/story?id=70085581

You seem to be coming down on the side of not gaining immunity from
this virus when the jury is still out...

I'd be glad to be wrong here, but is the way it looks to me. Immunity
is almost always limited to some degree, and it would seem that in the
case of Covid-19, it is quite limited. But as you say, the jury is
still out, and we won't know for sure for many months or even years - I
can only talk about indications.

Two links are of the same Korean report of 111 people who tested
positive after having the virus and testing negative.

"Health authorities here have said the virus was highly likely to
have been reactivated, instead of the people being reinfected, as
they tested positive again in a relatively short time after being
released from quarantine."

That is entirely possible - but really, it is just as bad. (Bad in
different ways, but still bad.) The key point (which we don't know at
all) is whether this can result in the person being infectious again
after having recovered from the illness, and whether it can result in
symptomatic problems again.

Again, this will all take time before we have the information. All I am
saying at the moment is that it would be unwise to base strategy on the
idea that people who have had the disease and recovered are immune, and
can't become ill again and can't spread it again.

(And this could also be a problem for vaccines - it may be hard to get
long-term immunity from a vaccine. For some diseases, this is solved by
having several vaccines over the course of months or a couple of years,
for others you need boosters every 5 or 10 years.)

The other two links are about an not peer reviewed study finding
"low" levels of antibodies in previously infected individuals with
zero clinical indication of reinfection. That is doubly lame.

It is all preliminary indications - I am not claiming anything else.

Add to this mixture the risk of the virus mutating - the more
people that get it, and the more time that goes past with
wide-scale infection, the bigger the chance of it mutating to
something that will then infect people anew.

Mutation is most likely a good thing. It is much less likely the
virus will widely mutate the antigens that produce the immune
response since there is currently very little selection pressure for
that with relatively small proportions of the population infected.
Mutating the impact of infection is much more likely since those who
show symptoms are quickly isolated and pass on the infection much
less often. Combine that will social distancing and the more
virulent forms see a higher selective pressure than less virulent
forms.

New variants through mutations do not necessarily reduce the levels of
the current strains. That depends on how similar they are in the
anti-bodies produced. If a milder but more infectious version mutates,
and it spreads further and faster, and people gain immunity to that, and
this immunity helps against the original more dangerous strains - /then/
the mutation is a good thing. That's a lot of "if"s.

On the other hand, if it does not confer immunity, there's another
disease going round. Even if it is mild, if the body is fighting one
infection then it is harder to fight off a new one (like the original
strain). Viruses in a body are additive, not competitive.

And if a new variant is more lethal, then the prime evolutionary
pressure on it is due to society dealing with an even more dangerous
virus. That might be bad for the virus in the long term, but in the
short term it's really bad for people.

Measles was almost eliminated by vaccines, but there so
many "anti-vaxer" morons that the elimination failed, and
there are still outbreaks - so kids still need the
vaccines. The same applies to polio.

Covid-19 can, hopefully, be eliminated by vaccines.
Whether it will or not is another matter - but good
vaccines will certainly prevent it being a problem.

But can Covid-19 be eliminated /without/ a vaccine? I
don't think so. It is far too wide-spread for that. It can
be kept at bay by other measures, and some places can be
kept free of it, but if there is freedom of movement,
outbreaks will always return.

Wide spread is not the issue. The shutdown will allow us to
get the numbers to a point that contact tracing can confine
the disease.

If South Korea can do it, why can't we?


Because you are only one country. To eliminate the virus
anywhere, it needs to be eliminated /everywhere/. Maybe the
USA can do the kind of tracking that South Korea managed (I
doubt it - Americans are not as obedient. Freedom works both
ways). But you won't get that same tracking across India,
Africa, war-torn Syria, Afghanistan, etc.

Ah, you are arguing semantics. Ok, fine. I'm talking about
eliminating it in various countries that are capable. The rest
of the world will deal with it for a while longer and have many
more deaths, but even there this disease will pass once it
infects enough people.


I won't say I am "arguing semantics", but the different terms and
viewpoints does at least partly explain why we appear to have
different opinions here.


Another aspect that is not yet understood is the long-term effects
on people that have had serious symptoms but recovered.
Preliminary indications are that it can involve not just lung
damage, but damage to the heart and liver (and this is not just for
people who needed ventilators).

Yep, that is not at all uncommon that a disease has subtle effects on
patients that remain even after being cured.

Indeed.

I suppose it could mutate and become infectious again after
passing through the lion's share of the world community. But
technically that is a new disease and a vaccine won't protect
from that either. Perhaps they will crack the code on developing
a vaccine to a slowly evolving antigen on the virus, but we've
not been able to do that with the cold or flu.

Even vaccines are no match for an evolving virus.


That depends on how the vaccine works (there are many paths to a
vaccine, and many are being researched concurrently for Covid-19).
Vaccines often target particular proteins on the virus shell - if
a mutation does not change that protein, the vaccine still works.
It is not uncommon that a vaccine can be of some benefit to a
related or mutated virus even if it is not a perfect match (that
happens when the estimates of yearly flu variants are not
accurate). And for some vaccine types, they can be made in a
flexible and adaptable way - like the flu vaccines, that can be
adapted for different mutations in a few months.

Vaccines are not perfect (especially when we don't have one), but
they are the best tool we have against viruses.

You seem to be walking down both sides of the street. Mutations are
random and frequent in viruses.

Yes.

It is then up to selective pressure
to spread a mutation through the population if it "improves" the
virus, meaning more likely to reproduce.

Yes.

As I've already indicated
there is little selective pressure to promote mutations involving
resistance to a vaccine we don't yet have.

Yes.

If the virus infection
rate is low when we develop and use the vaccine there is less
opportunity for it to mutate.

Yes.

Working to eliminate the virus from
each country is a win-win.

Absolutely.

Lower infection rates = fewer deaths and
less opportunity for the virus to mutate once we have a vaccine.

That is all correct.

I am not recommending we do nothing until a vaccine is available! I
agree with all your recommendations and strategies - but I don't think
we will get out of this mess properly until we have a vaccine as well.

 

On Wed, 15 Apr 2020 08:47:31 +0100, Martin Brown
<'''newspam'''@nezumi.demon.co.uk> wrote:

On 12/04/2020 17:32, jlarkin@highlandsniptechnology.com wrote:
On Sun, 12 Apr 2020 09:39:02 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 10/04/2020 18:01, jlarkin@highlandsniptechnology.com wrote:
On Fri, 10 Apr 2020 16:46:23 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 10/04/2020 16:06, jlarkin@highlandsniptechnology.com wrote:

Test density is increasing exponentially but case rates are not
adjusted. My guesses are as good as anybody else' now.

No. You are woefully ignorant and *very* determined to remain so.

The German health system has run an antibody test in one of the hottest
spots on the planet and found that only 14% of the population has
actually got antibodies to the virus at present.

https://www.technologyreview.com/2020/04/09/999015/blood-tests-show-15-of-people-are-now-immune-to-covid-19-in-one-town-in-germany/

That's a useful bit of data. Prefacing it with "willfully ignorant"
isn't. I didn't deliberately avoid seeing the German data.

You cherry pick data to suit your argument so often that it is difficult
to tell whether you are unaware of the scientific data or deliberately
refusing to look at it. You are a science denier at heart.

I consider a lot of data and speculate about possible dynamics. That
is not an "argument." I could make an argument, but I haven't. I'd
probably wind up being wrong. I hate to be wrong, because it suggests
a lapse of good thinking.

You have been claiming that it would all be fine and there was nothing
to worry about for ages.

No. I have been suggesting that this *could* be just another bad
winter cold that was unfortunate to be born in a slow press cycle. I
have made no "claims."

Take a look at this:

https://coronavirus.jhu.edu/map.html

World daily cases peaked 10 days ago and is down. Most european
countries are well past peak, some now below 10% of peak; the ones
that started sooner are down most.

The US case rate is declining and has been basically flat for about 2
weeks now, peaked about April 10. This dropoff, if it continues, will
disappoint some people.

I still think the curves should be scaled by test density, which would
change their shapes radically.

Worry? Personally, I don't worry about much of anything. I guess that
changes my judgements. Fear always overpowers observation and reason.

Somebody should wait a while and do some serious research and write a
book about this event. There is obviously an immense amount of bad
data and "scientific" wrongness and panic circulating now.

That's the way some people design electronics: consider as many
outrageous possibilities as you can, and analyze the consequences of
each. Considering unsanctioned alternatives offends most people.

"Science teaches us to doubt." Or should.

There is a difference between doubting something and going round with
your eyes shut and fingers in your ears impervious to all new data.

That statement is absolutely correct. Doubt should be liberating. It
should break the static friction of what everybody knows. It should
encourage all possible speculations that you can manage, especially
goofy ones. You can sort them out before you etch boards.

I was just talking to The Brat about that. The virus is doing some
harm, but it's also breaking a lot of social static friction. I'm not
about to predict how that is likely to settle out.

I do think that a lot of arguably silly small businesses, goofy
boutiques and bad restaurants, won't come back.






--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Bill Sloman]

On Thursday, April 16, 2020 at 1:00:08 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Wed, 15 Apr 2020 08:47:31 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:
On 12/04/2020 17:32, jlarkin@highlandsniptechnology.com wrote:
On Sun, 12 Apr 2020 09:39:02 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:
On 10/04/2020 18:01, jlarkin@highlandsniptechnology.com wrote:
On Fri, 10 Apr 2020 16:46:23 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:
On 10/04/2020 16:06, jlarkin@highlandsniptechnology.com wrote:

You have been claiming that it would all be fine and there was nothing
to worry about for ages.

No. I have been suggesting that this *could* be just another bad
winter cold that was unfortunate to be born in a slow press cycle.

Which means that you haven't paying attention to any serious reports about the subject.

> I have made no "claims."

But even making the suggestion demonstrates a massive disconnection from reality.

Take a look at this:

https://coronavirus.jhu.edu/map.html

World daily cases peaked 10 days ago and is down. Most european
countries are well past peak, some now below 10% of peak; the ones
that started sooner are down most.

Sadly, that isn't the number that matters. Daily cases stop rising when the countries involved get frightened enough to make the short term social changes that get the number of people infected by each new case below one.

They got to get it well below one before the epidemic stops killing lots of people. That can take time - look at Italy's dismal record.

https://www.worldometers.info/coronavirus/country/italy/

The US is looking just as bad.

The US case rate is declining and has been basically flat for about 2
weeks now, peaked about April 10. This drop-off, if it continues, will
disappoint some people.

When I last looked, half the US case were in New York, New Jersey and Louisiana, which contain 10% of the US population. If the epidemic gets going in adjacent states there will be a whole lot more state administrations who will have to scared into slowing down their economies to save a few more lives.

It would be nice to think that this isn't going to happen, but American exceptionalism has killed a great many Americans by discouraging them from adopting solutions that work fine everywhere else.

I still think the curves should be scaled by test density, which would
change their shapes radically.

More Pollyanna idiocy. Places doing serious testing get about 2% positive outcomes. The US is testing fewer people per million than most advanced industrial countries - it's just behind Russia - but it's testing enough that testing density isn't going to make much difference.

Worry? Personally, I don't worry about much of anything. I guess that
changes my judgements. Fear always overpowers observation and reason.

John Larkin doesn't observe much, and seems incapable of using reason to make sense of what he ought to be able to observe.

Somebody should wait a while and do some serious research and write a
book about this event. There is obviously an immense amount of bad
data and "scientific" wrongness and panic circulating now.

Stopping people getting infected by the virus and ending up dead is a more urgent task, right now. Getting a vaccine is pretty urgent too.

https://www.pnas.org/content/pnas/early/2020/03/27/2005456117.full.pdf

Your book will probably get written. It isn't going find nearly as much wrongness and panic as you are currently imagining. Trump isn't going to come out of it well.

<snip>

"Science teaches us to doubt." Or should.

There is a difference between doubting something and going round with
your eyes shut and fingers in your ears impervious to all new data.

That statement is absolutely correct. Doubt should be liberating. It
should break the static friction of what everybody knows. It should
encourage all possible speculations that you can manage, especially
goofy ones. You can sort them out before you etch boards.

It pays to know a bit more about what you are speculating about than you seem to be able to manage.

I was just talking to The Brat about that. The virus is doing some
harm, but it's also breaking a lot of social static friction. I'm not
about to predict how that is likely to settle out.

A sudden bout of self-restraint? Unexpected.

I do think that a lot of arguably silly small businesses, goofy
boutiques and bad restaurants, won't come back.

Bad restaurants don't need an epidemic to go bust. Goofy boutiques do tend to look a lot goofier to people who wouldn't buy what they sell.

--
Bill Sloman, Sydney

 

[Ricky C]

On Wednesday, April 15, 2020 at 5:29:51 AM UTC-4, David Brown wrote:

On 14/04/2020 22:20, Ricky C wrote:
On Tuesday, April 14, 2020 at 6:30:21 AM UTC-4, David Brown wrote:
On 13/04/2020 19:16, Ricky C wrote:
On Monday, April 13, 2020 at 10:25:05 AM UTC-4, David Brown
wrote:
On 12/04/2020 21:28, Ricky C wrote:
On Sunday, April 12, 2020 at 12:27:45 PM UTC-4, David Brown
wrote:
On 12/04/2020 04:52, Ricky C wrote:


snip


Those "few things" would include banning all travel into the
virus-free area. Clearly, that is never going to be practical.
The reality will involve a balance between reducing the risk of the
infection re-occurring in the area, and practicality.

Not "banning" travel, but restricting it and requiring quarantine
along with the ever essential contact tracing if the virus does make
it in.


Even if tests can get good enough that quarantine can be reduced to a
few days, it would be massively intrusive. (And tests are currently
/not/ good enough - we have top-range RNA tests in Norway, and they have
false negatives as well as false positives. We can hope for better
tests, but at least one false positive case appears to be due to the
virus being in the person's lower lungs but not upper airway.)

Yup, nothing is perfect. That's why no matter what we do we will need to improve and continue some practices. For example, I expect the shields put up in front of the cashier at the super market will remain. Yes, we can never go back to the same ways of doing things. Travel to a country that still has cases of COVID-19 and on return you will be in quarantine for two weeks. Sorry, that's life!

Contact tracing depends on voluntary cooperation. Will that be good
enough? Maybe - it depends on the level of risk you are willing to accept.

In China you don't go anywhere unless your phone app says you are safe and it tracks everywhere you go. Google and Apple are working on similar apps. Again, this will be the new normal. Automatic contact tracing by the Internet.

Such a myopic "I only care about me and those around me" attitude
is the best guarantee of not getting control of the virus.

It is the only realistic way of dealing with it. The bottom line is
you can control your country, but not others. So act accordingly.
Thinking you can do anything about the rest of the world is a
fantasy.


Helping other countries is entirely possible - and the weaker, poorer
and less stable countries of the world won't have a chance of
eliminating the virus (with or without vaccines) without help. You are
right that you can't /control/ other countries, but you /can/ help them.

I never said we can't or shouldn't try. But you can only help those who are willing. I'm sure you read about the problems we had trying to help some African countries with HIV. We also had trouble with Ebola.

None of that is relevant to the issue of riding any given country of COVID-19.

If you want to avoid the virus re-occurring in the USA (assuming
you first manage to eliminate it there without a vaccine - and
that's a big assumption), you have two choices. Seal off the
borders of the USA permanently with quarantines and comprehensive
tests for all international travel (good luck with your wall), or
work towards eliminating it /everywhere/ throughout the world.

I've already explained why your ideas are draconian, but now you seem
to get it. Quarantine, testing and contact tracing. They work.
Just ask China.


Parts of China are still on lockdown, and movement into the country is
highly restricted.

Yup, because those regions still have not be rid of the virus. China is being rational and not trying to use a one size fits all approach to dealing with the infection. They've rid Hubei of the disease (or maybe it's only Wuhan, not sure) and have opened up business there, so they are showing it can be done.

I agree that you can come a long way without a vaccine - if your country
is willing and able to take the necessary steps, and especially if it
starts soon enough (a bit late for that now in the USA).

To late for NYC to prevent ICU overloads, but not for getting rid of the virus. That's what we were talking about. Getting rid of it and maintaining that isolation from the world.

But without a vaccine - without /knowing/ that the virus is not found
elsewhere, and so will not turn up in your own country - you will always
be on alert, suspicious of travellers and foreigners, monitored and
tracked, and restricted in your way of life.

Yes, we will always be wary of this disease just as we are many, many other diseases. What happens when Ebola breaks out in some part of Africa? We issue travel restrictions and screen anyone suspected of having the disease.. For COVID-19 the restrictions will need to be more severe.

Obviously the reality will be a compromise and a balance of risks -
if the disease can be eliminated from /most/ of the world, the
risks of travellers spreading it is much smaller, and it can be
good enough to live with. (That is the situation for many serious
diseases, such as Ebola.)

There is not much choice. We don't have a vaccine. So the only
solutions are what I'm suggesting.


Currently, yes, absolutely.

Then there's not much to debate, is there?

As for letting it "burn out", what exactly do you mean by that? We
now know that having the virus does not impart full immunity - we
don't yet know how much or how little you get. There are plenty of
viruses for which you get immunity for a year or so, and it flares
up on two-year cycles.

It is typical for such viruses to mutate to less lethal forms. The
most effective form of the virus is one that barely makes you sick so
it can be transmitted while people continue their normal lives. So
the virus has selective pressure for that.

Over the long term in a natural environment, that is correct - viruses
and their hosts evolve together to form a stable bias. In the shorter
term, there are no biases - mutations are random. (That does not mean
there are equal chances of a new variant being more or less harmful -
merely that we need to think of the short-term potentials as well as
what will happen over the next few hundred thousand years.)

Mutations are always random. Selection is what determines which mutations spread through the population. Viruses mutate MUCH more rapidly as well as reproduce much more rapidly than animals and plants. So instead of requiring millennia it only requires weeks or months for significant change to take place. There are already many varieties of SARS-CoV-2. They just don't behave much differently... yet. Someone posted a link to a map showing the geographical spread of the mutations.

We never developed a treatment or an effective vaccine for the swine
flu. It is still with us circulating the globe, yet no one seems to
notice.

There /was/ a reasonably effective vaccine against swine flu in 2009,
and it was widely used - like most people in this country, I've had it.
It greatly reduced the spread of the virus.

You have an interesting definition of "effective". There were two vaccines.. One providing protection to roughly 50% and the other providing protection to roughly 30%. These are herd immunity vaccines. Individuals aren't protected, but there is enough immunity to lower R0 to less than 1.0.

So your last statement is correct, it reduced the spread of the disease. Just don't assume you are protected.

No one is particularly concerned about swine flu because it is very mild
- significantly less virulent than normal seasonal flu, though more
infectious. And a fair proportion of people have a natural immunity,
due to its similarities to other flu viruses. The prime concerns during
that pandemic were the disruption to economies from many people getting
ill at once (in bed for a week ill, not hospitalised ill), and the risk
of it mutating.

That's not really relevant to COVID-19.

BTW, where did you read having this virus does not impart full
immunity??? I haven't seen that. So far everyone is saying they
don't know.


Mostly it is still a case of "we don't know". But there have been
follow-up tests (mostly in China and South Korea so far, since they had
earlier cases) of people who have had the virus and recovered, and in
about 30% of the people they found little or no antibodies. That is
just weeks after recovery. People have also been found to have been
infected again, after having recovered. (I gave some links earlier, but
I'm sure you can find some English-language Korean articles, or reports
in English-language journals or newspapers that you trust. I have
certainly seen them in Norwegian sources.)

I already responded about the links. They don't say what you seem to be saying. Counting antibodies is not a good way to measure immunity. The immune system "learns" about the antigen and can gear up to make antibodies much more quickly after an infection. At least that's what they taught us in college 40 years ago.

I don't recall what the issue was with the other two articles if they are the ones I'm thinking of.

It is clearly too early to be sure of anything here. The numbers tested
were small, there hasn't been a long time passed since people have been
recovering, and most countries are concentrating on dealing with sick
people rather than testing recovered people.

What we /do/ know is that there are strong indications that immunity
will be partial, incomplete and limited.

No, none of that is true.

(Immunity from past diseases is almost always limited - good enough to
make your chances of reinfection small, but not nearly as complete and
lasting as commonly thought.)

In terms of individuals that may be true, but not so for populations. Think herd immunity.

Maybe this will all be controllable and containable. Maybe better
control on travelling, better hygiene habits, permanent contact
tracing of populations, etc., will mean that as we see new
outbreaks around the world, there won't be much of it spreading in
the USA. There are a lot of unknown variables here - a lot of
maybes. I am fairly confident that a reasonable balance will be
established in time.

But a good vaccine would make all the difference.

I believe the expected date is 2021 or 2022.

Dates are a bit of a guesswork here - it will be ready when it's ready.
But those are the estimates, yes. If we keep funding vaccine
development and work in parallel on the various possible strategies, we
maximise the chance that at least one of them will work well.

Bill Gates has the right idea. (He made his fortune through theft, cons
and crime, but he is doing a lot of good with the money now.) The Gates
Foundation is paying towards building vaccine factories before we know
which ones will work, to minimise the time to production.

https://www.weforum.org/agenda/2020/04/bill-gates-7-potential-coronavirus-vaccines/




(This is my estimation and extrapolation, rather than a known
fact.)

Remember, recovery from Covid-19 does not appear to give very
good immunity - so all you need is a few pockets of it hidden
away somewhere, and the potential for new outbreaks will be
there.

(One can hope that they would be caught and isolated faster
now, of course.)

Where did you see any indication that the disease does not leave
the person immune? I have not seen that at all.


This is a crucial point. I think you'd agree with me more above if
you understood this.

For some diseases, after recovery you have long-term immunity with
antibodies. For other diseases, the immunity is short-term or
only partial. It is a common assumption - but often incorrect -
that if you've had a disease, you are immune for life (given a
consistent pathogen - flu's and colds are caused by lots of related
viruses). It is this assumption that led to the "everyone's going
to get it sooner or later - let people get it and build up a herd
immunity" strategy used by some countries.

The assumption is no more than that - an assumption. It often does
not apply.

And it does not /seem/ to apply for Covid-19.

The studies are early as yet - we'll need many more, and it's
impossible to evaluate long-term immunity without waiting a long
time. But preliminary testing is showing unexpectedly low
anti-body counts in a sizeable fraction of people who have
recovered from the disease.

We don't yet know how this will work out. Maybe people will have
enough immunity that re-infections will be mild or symptomless.
Maybe new infections will boost the immune response to give a
longer term immunity after the second round. But maybe
re-infections will leave people with mild (or different) symptoms
but still infectious.


https://time.com/5810454/coronavirus-immunity-reinfection/
http://www.koreaherald.com/view.php?ud=20200412000213&np=3&mp=1
https://www.telegraph.co.uk/science/2020/04/08/coronavirus-immunity-test-faces-setback-recovered-patients-present/


https://abcnews.go.com/Health/questions-remain-covid-19-recovery-guarantee-immunity-reinfection/story?id=70085581

You seem to be coming down on the side of not gaining immunity from
this virus when the jury is still out...

I'd be glad to be wrong here, but is the way it looks to me. Immunity
is almost always limited to some degree, and it would seem that in the
case of Covid-19, it is quite limited. But as you say, the jury is
still out, and we won't know for sure for many months or even years - I
can only talk about indications.

There is virtually no evidence regarding that. Why not wait until there is reasonable research results? It won't take years. We will know soon enough.

I remember the other two papers now, people seemingly being reinfected. These papers said they could be sure it was actually a reinfection rather than a reemergence of the original infection. Oh, there it is just below, a quote from the paper.

Two links are of the same Korean report of 111 people who tested
positive after having the virus and testing negative.

"Health authorities here have said the virus was highly likely to
have been reactivated, instead of the people being reinfected, as
they tested positive again in a relatively short time after being
released from quarantine."

That is entirely possible - but really, it is just as bad. (Bad in
different ways, but still bad.) The key point (which we don't know at
all) is whether this can result in the person being infectious again
after having recovered from the illness, and whether it can result in
symptomatic problems again.

Not good, but not all that terrible. You seem to think in terms of absolutes. We don't need a perfect barrier. We don't need perfect tests. We need to take measures that will reduce the infection rate to very low levels and keep it there as they have done in China. Once we have that, we can eliminate it from inside the US and deal with any infections that make it into the US by the same method.

It is the lock downs that will get us to low levels if we are strong enough to follow through.

Again, this will all take time before we have the information. All I am
saying at the moment is that it would be unwise to base strategy on the
idea that people who have had the disease and recovered are immune, and
can't become ill again and can't spread it again.

I'm not sure what you are referring to. I never said anything about it. The number of immune people is a very small fraction of the population, so it is of no real value.

(And this could also be a problem for vaccines - it may be hard to get
long-term immunity from a vaccine. For some diseases, this is solved by
having several vaccines over the course of months or a couple of years,
for others you need boosters every 5 or 10 years.)

Vaccines don't have to work the way natural immunity does. Vaccines can be targeted to specific antigens that we know and understand and even extend to other diseases. We also know something about which antigens can mutate and which can't. If the antigen is essential to the function of the virus it can't both mutate and produce a viable virus.

The other two links are about an not peer reviewed study finding
"low" levels of antibodies in previously infected individuals with
zero clinical indication of reinfection. That is doubly lame.


It is all preliminary indications - I am not claiming anything else.

Not sure what that means. Above you said, "Immunity is almost always limited to some degree, and it would seem that in the case of Covid-19, it is quite limited." and other, similar statements. I think you are giving these reports far too much credence. You need to understand what Larkin doesn't, that one swallow does not a summer make. Scientific research works by lots of small movements, some forward, some sideways, some backwards. But the net motion, not unlike evolution, is forward. Just don't pay too much attention to the Brownian motion while waiting to see the larger movements.

Add to this mixture the risk of the virus mutating - the more
people that get it, and the more time that goes past with
wide-scale infection, the bigger the chance of it mutating to
something that will then infect people anew.

Mutation is most likely a good thing. It is much less likely the
virus will widely mutate the antigens that produce the immune
response since there is currently very little selection pressure for
that with relatively small proportions of the population infected.
Mutating the impact of infection is much more likely since those who
show symptoms are quickly isolated and pass on the infection much
less often. Combine that will social distancing and the more
virulent forms see a higher selective pressure than less virulent
forms.


New variants through mutations do not necessarily reduce the levels of
the current strains. That depends on how similar they are in the
anti-bodies produced. If a milder but more infectious version mutates,
and it spreads further and faster, and people gain immunity to that, and
this immunity helps against the original more dangerous strains - /then/
the mutation is a good thing. That's a lot of "if"s.

There is no reason to think the virus has evolved to produce different antibodies.

On the other hand, if it does not confer immunity, there's another
disease going round. Even if it is mild, if the body is fighting one
infection then it is harder to fight off a new one (like the original
strain). Viruses in a body are additive, not competitive.

Anything is possible. Flu vaccines sometimes fail because there are multiple strains in play and the vaccine makers back the wrong horse.

And if a new variant is more lethal, then the prime evolutionary
pressure on it is due to society dealing with an even more dangerous
virus. That might be bad for the virus in the long term, but in the
short term it's really bad for people.

We are talking about containing the virus. There are lots of things that are bad in the world, but not relevant.

Measles was almost eliminated by vaccines, but there so
many "anti-vaxer" morons that the elimination failed, and
there are still outbreaks - so kids still need the
vaccines. The same applies to polio.

Covid-19 can, hopefully, be eliminated by vaccines.
Whether it will or not is another matter - but good
vaccines will certainly prevent it being a problem.

But can Covid-19 be eliminated /without/ a vaccine? I
don't think so. It is far too wide-spread for that. It can
be kept at bay by other measures, and some places can be
kept free of it, but if there is freedom of movement,
outbreaks will always return.

Wide spread is not the issue. The shutdown will allow us to
get the numbers to a point that contact tracing can confine
the disease.

If South Korea can do it, why can't we?


Because you are only one country. To eliminate the virus
anywhere, it needs to be eliminated /everywhere/. Maybe the
USA can do the kind of tracking that South Korea managed (I
doubt it - Americans are not as obedient. Freedom works both
ways). But you won't get that same tracking across India,
Africa, war-torn Syria, Afghanistan, etc.

Ah, you are arguing semantics. Ok, fine. I'm talking about
eliminating it in various countries that are capable. The rest
of the world will deal with it for a while longer and have many
more deaths, but even there this disease will pass once it
infects enough people.


I won't say I am "arguing semantics", but the different terms and
viewpoints does at least partly explain why we appear to have
different opinions here.


Another aspect that is not yet understood is the long-term effects
on people that have had serious symptoms but recovered.
Preliminary indications are that it can involve not just lung
damage, but damage to the heart and liver (and this is not just for
people who needed ventilators).

Yep, that is not at all uncommon that a disease has subtle effects on
patients that remain even after being cured.


Indeed.


I suppose it could mutate and become infectious again after
passing through the lion's share of the world community. But
technically that is a new disease and a vaccine won't protect
from that either. Perhaps they will crack the code on developing
a vaccine to a slowly evolving antigen on the virus, but we've
not been able to do that with the cold or flu.

Even vaccines are no match for an evolving virus.


That depends on how the vaccine works (there are many paths to a
vaccine, and many are being researched concurrently for Covid-19).
Vaccines often target particular proteins on the virus shell - if
a mutation does not change that protein, the vaccine still works.
It is not uncommon that a vaccine can be of some benefit to a
related or mutated virus even if it is not a perfect match (that
happens when the estimates of yearly flu variants are not
accurate). And for some vaccine types, they can be made in a
flexible and adaptable way - like the flu vaccines, that can be
adapted for different mutations in a few months.

Vaccines are not perfect (especially when we don't have one), but
they are the best tool we have against viruses.

You seem to be walking down both sides of the street. Mutations are
random and frequent in viruses.

Yes.

It is then up to selective pressure
to spread a mutation through the population if it "improves" the
virus, meaning more likely to reproduce.

Yes.

As I've already indicated
there is little selective pressure to promote mutations involving
resistance to a vaccine we don't yet have.

Yes.

If the virus infection
rate is low when we develop and use the vaccine there is less
opportunity for it to mutate.

Yes.

Working to eliminate the virus from
each country is a win-win.

Absolutely.

Lower infection rates = fewer deaths and
less opportunity for the virus to mutate once we have a vaccine.


That is all correct.

I am not recommending we do nothing until a vaccine is available! I
agree with all your recommendations and strategies - but I don't think
we will get out of this mess properly until we have a vaccine as well.

We will see. In the mean time we need to take rational actions and not rush into anything as we seem to want to do to save the economy. Who knows, maybe it's a lose-lose scenario where there is no happy middle and we are doomed to both be ravished by this disease and crash the economy.

I thinking we have covered everything there is to cover on this topic.

--

Rick C.

+---+ Get 1,000 miles of free Supercharging
+---+ Tesla referral code - https://ts.la/richard11209

 

[whit3rd]

On Tuesday, April 14, 2020 at 11:12:16 PM UTC-7, Ricky C wrote:

On Wednesday, April 15, 2020 at 2:00:05 AM UTC-4, whit3rd wrote:
On Tuesday, April 14, 2020 at 5:54:35 PM UTC-7, Ricky C wrote:

So what will you have third world countries do where the full population don't even have access to running water or other means of sanitation???

Send in a mobile team to set up vaccination centers? Sanitation in sparse population areas isn't
really involved, but local market centers ought to have a priority on preventive care.

Of course sanitation is essential. You seem to forget that a very important part of reducing the spread of this disease is hand washing... proper hygiene.

Sanitation, to me, means sewage treatment... the soap vulnerability is only one attack, for
all I know an oil rub, or some leaves, could be effective as well. The virus is fragile.

As already stated, the virus is not likely to be eliminated from the planet. So the alternative is to make your country safe.

Not really an 'alternative' that can work. We don't have lots of nations on this planet that
have all their resources and products produced and consumed locally; even Rome had to
trade with Wales to get their tin. Nations don't entirely stand alone, they shop abroad.

I almost think you are just trying to play dumb. No one said trade had to stop.

So, how do you visit the trade fair, or inspect a manufacturer, with multiple nations
deciding on your travel and border-crossing requirements? Who is allowed to
crew the ships and aircraft that visit port after port? International accommodation of
visits is essential, and trade DOES stop rather easily if you decide not to trust
a screen image.

 

[David Brown]

On 15/04/2020 19:09, Ricky C wrote:

On Wednesday, April 15, 2020 at 5:29:51 AM UTC-4, David Brown wrote:
On 14/04/2020 22:20, Ricky C wrote:
On Tuesday, April 14, 2020 at 6:30:21 AM UTC-4, David Brown wrote:
On 13/04/2020 19:16, Ricky C wrote:
On Monday, April 13, 2020 at 10:25:05 AM UTC-4, David Brown
wrote:
On 12/04/2020 21:28, Ricky C wrote:
On Sunday, April 12, 2020 at 12:27:45 PM UTC-4, David Brown
wrote:
On 12/04/2020 04:52, Ricky C wrote:


snip

I'm going to snip lots of this, because I agree with most of what you
write and the posts are getting ridiculously long.

Parts of China are still on lockdown, and movement into the country is
highly restricted.

Yup, because those regions still have not be rid of the virus. China is being rational and not trying to use a one size fits all approach to dealing with the infection. They've rid Hubei of the disease (or maybe it's only Wuhan, not sure) and have opened up business there, so they are showing it can be done.

China's a big place, and a very diverse place - more so than the USA, I
think. In Western media and thinking, it is often lumped together as
though it were one homogenous place. It makes a lot of sense for them
to treat different parts of their country in different ways here.

I agree that you can come a long way without a vaccine - if your country
is willing and able to take the necessary steps, and especially if it
starts soon enough (a bit late for that now in the USA).

To late for NYC to prevent ICU overloads, but not for getting rid of the virus. That's what we were talking about. Getting rid of it and maintaining that isolation from the world.

We'll see. (I hope you are right, obviously.)

But without a vaccine - without /knowing/ that the virus is not found
elsewhere, and so will not turn up in your own country - you will always
be on alert, suspicious of travellers and foreigners, monitored and
tracked, and restricted in your way of life.

Yes, we will always be wary of this disease just as we are many, many other diseases. What happens when Ebola breaks out in some part of Africa? We issue travel restrictions and screen anyone suspected of having the disease. For COVID-19 the restrictions will need to be more severe.

One good thing we can hope for out of all this mess is that we (the
world) should be better equipped to handle other disease outbreaks in
the future. Covid-19 is not as lethal as some of the diseases around -
it can be viewed as a practice run. When someone with Ebola comes over
from Africa to the USA, and spreads it to a thousand people in a big
church service or sports event, I hope the experience of Covid-19 means
hospitals will be better equipped and authorities can react faster and
more effectively.

It is typical for such viruses to mutate to less lethal forms. The
most effective form of the virus is one that barely makes you sick so
it can be transmitted while people continue their normal lives. So
the virus has selective pressure for that.

Over the long term in a natural environment, that is correct - viruses
and their hosts evolve together to form a stable bias. In the shorter
term, there are no biases - mutations are random. (That does not mean
there are equal chances of a new variant being more or less harmful -
merely that we need to think of the short-term potentials as well as
what will happen over the next few hundred thousand years.)

Mutations are always random. Selection is what determines which mutations spread through the population. Viruses mutate MUCH more rapidly as well as reproduce much more rapidly than animals and plants. So instead of requiring millennia it only requires weeks or months for significant change to take place. There are already many varieties of SARS-CoV-2. They just don't behave much differently... yet. Someone posted a link to a map showing the geographical spread of the mutations.

Evolution towards a low-level endemic infection of a pathogen involves
evolution in the pathogen and the host. It's the evolution of the host
species that takes a very long time here.

There is no environmental pressure to select for milder symptoms on the
virus itself, until you are talking about the level of lethality where
the host dies before being able to spread the disease. As long as each
host spreads the disease to an average of more than one new host before
they die, the pathogen is doing fine. Evolution does not "think ahead"
- it is not guided by long-term planning, such as keeping hosts alive
for the next generation.

The intervention of human intelligence changes things a little - the
pathogen does not have to be as deadly before we humans apply measures
to stop the spread. If a strain of SARS-CoV-2 mutated to be
significantly more lethal, then maybe we'd put more effort into stopping
that strain and it would die out - that would be evolutionary pressure
against it.

But milder forms don't have a positive evolutionary pressure - the
lethality of a disease has little effect on its success. The
infectiousness of the disease is what counts for evolution.

Most mutations in any living organism or virus result in failure - the
organism does not survive, or the virus is not viable. Of the remaining
mutations, most weaken what was already a fairly successful genome. Of
those that still remain, most have little noticeable effect.

There have been a fair number of variations of SARS-CoV-2 found, as
expected. There is little significant difference between them - except
from a split early on, where the mutated version was more severe and
more infectious, and is thus the form that is most common.

We never developed a treatment or an effective vaccine for the swine
flu. It is still with us circulating the globe, yet no one seems to
notice.

There /was/ a reasonably effective vaccine against swine flu in 2009,
and it was widely used - like most people in this country, I've had it.
It greatly reduced the spread of the virus.

You have an interesting definition of "effective". There were two vaccines. One providing protection to roughly 50% and the other providing protection to roughly 30%. These are herd immunity vaccines. Individuals aren't protected, but there is enough immunity to lower R0 to less than 1.0.

So your last statement is correct, it reduced the spread of the disease. Just don't assume you are protected.

That is the way of all vaccines. (Though the protection rate varies.)

It is clearly too early to be sure of anything here. The numbers tested
were small, there hasn't been a long time passed since people have been
recovering, and most countries are concentrating on dealing with sick
people rather than testing recovered people.

What we /do/ know is that there are strong indications that immunity
will be partial, incomplete and limited.

No, none of that is true.

That is not the message I am getting from articles I read. But let us
postpone this until we know more.

(Immunity from past diseases is almost always limited - good enough to
make your chances of reinfection small, but not nearly as complete and
lasting as commonly thought.)

In terms of individuals that may be true, but not so for populations. Think herd immunity.

Herd immunity is a balance between the average individual immunity and
the disease infectivity.

I'd be glad to be wrong here, but is the way it looks to me. Immunity
is almost always limited to some degree, and it would seem that in the
case of Covid-19, it is quite limited. But as you say, the jury is
still out, and we won't know for sure for many months or even years - I
can only talk about indications.

There is virtually no evidence regarding that. Why not wait until there is reasonable research results? It won't take years. We will know soon enough.

It /will/ take years to know how the immunity varies over years. But it
will not take that long to get some estimates, and a lot more information.

Ideally, we need the information quickly - it is critical to being able
to view recovered people as immune, unable to get or spread the
infection (meaning they can work in a hospital with no risk to
themselves, for example).

I remember the other two papers now, people seemingly being reinfected. These papers said they could be sure it was actually a reinfection rather than a reemergence of the original infection. Oh, there it is just below, a quote from the paper.


Two links are of the same Korean report of 111 people who tested
positive after having the virus and testing negative.

"Health authorities here have said the virus was highly likely to
have been reactivated, instead of the people being reinfected, as
they tested positive again in a relatively short time after being
released from quarantine."

That is entirely possible - but really, it is just as bad. (Bad in
different ways, but still bad.) The key point (which we don't know at
all) is whether this can result in the person being infectious again
after having recovered from the illness, and whether it can result in
symptomatic problems again.

Not good, but not all that terrible. You seem to think in terms of absolutes. We don't need a perfect barrier. We don't need perfect tests. We need to take measures that will reduce the infection rate to very low levels and keep it there as they have done in China. Once we have that, we can eliminate it from inside the US and deal with any infections that make it into the US by the same method.

I'd rather see an absolute elimination of the disease - but I'll be
happy with a good reduction and containment.

It is the lock downs that will get us to low levels if we are strong enough to follow through.

Agreed.

Again, this will all take time before we have the information. All I am
saying at the moment is that it would be unwise to base strategy on the
idea that people who have had the disease and recovered are immune, and
can't become ill again and can't spread it again.

I'm not sure what you are referring to. I never said anything about it. The number of immune people is a very small fraction of the population, so it is of no real value.

No, you did not say that - I did not imply that you did. But it has
been the basic strategy for some countries' initial response to the
disease (such as the UK).

(And this could also be a problem for vaccines - it may be hard to get
long-term immunity from a vaccine. For some diseases, this is solved by
having several vaccines over the course of months or a couple of years,
for others you need boosters every 5 or 10 years.)

Vaccines don't have to work the way natural immunity does. Vaccines can be targeted to specific antigens that we know and understand and even extend to other diseases. We also know something about which antigens can mutate and which can't. If the antigen is essential to the function of the virus it can't both mutate and produce a viable virus.

Correct. But to develop (or pick) a good vaccine, it is useful to know
the details of the natural immune response - what the antibodies target,
and how well that immunity lasts. Then we can try and provoke a better
immune response.

The other two links are about an not peer reviewed study finding
"low" levels of antibodies in previously infected individuals with
zero clinical indication of reinfection. That is doubly lame.


It is all preliminary indications - I am not claiming anything else.

Not sure what that means. Above you said, "Immunity is almost always limited to some degree, and it would seem that in the case of Covid-19, it is quite limited." and other, similar statements. I think you are giving these reports far too much credence. You need to understand what Larkin doesn't, that one swallow does not a summer make. Scientific research works by lots of small movements, some forward, some sideways, some backwards. But the net motion, not unlike evolution, is forward. Just don't pay too much attention to the Brownian motion while waiting to see the larger movements.

I am entirely aware of that.

The picture I am seeing at the moment, from a number of things I have
read, is that immunity from Covid-19 is likely to be limited. I may be
interpreting incorrectly, I may be putting too much weight on particular
sources, I may be too pessimistic here. It is too early to be sure, and
I will update my picture as time goes by.

I am not recommending we do nothing until a vaccine is available! I
agree with all your recommendations and strategies - but I don't think
we will get out of this mess properly until we have a vaccine as well.

We will see. In the mean time we need to take rational actions and not rush into anything as we seem to want to do to save the economy. Who knows, maybe it's a lose-lose scenario where there is no happy middle and we are doomed to both be ravished by this disease and crash the economy.

Agreed.

I thinking we have covered everything there is to cover on this topic.

Fair enough - even with the snipping I made, the post is still long.

I am sure we will pick it up again when we know more.

 

[John Larkin]

On Wed, 15 Apr 2020 07:59:57 -0700, jlarkin@highlandsniptechnology.com
wrote:

On Wed, 15 Apr 2020 08:47:31 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 12/04/2020 17:32, jlarkin@highlandsniptechnology.com wrote:
On Sun, 12 Apr 2020 09:39:02 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 10/04/2020 18:01, jlarkin@highlandsniptechnology.com wrote:
On Fri, 10 Apr 2020 16:46:23 +0100, Martin Brown
'''newspam'''@nezumi.demon.co.uk> wrote:

On 10/04/2020 16:06, jlarkin@highlandsniptechnology.com wrote:

Test density is increasing exponentially but case rates are not
adjusted. My guesses are as good as anybody else' now.

No. You are woefully ignorant and *very* determined to remain so.

The German health system has run an antibody test in one of the hottest
spots on the planet and found that only 14% of the population has
actually got antibodies to the virus at present.

https://www.technologyreview.com/2020/04/09/999015/blood-tests-show-15-of-people-are-now-immune-to-covid-19-in-one-town-in-germany/

That's a useful bit of data. Prefacing it with "willfully ignorant"
isn't. I didn't deliberately avoid seeing the German data.

You cherry pick data to suit your argument so often that it is difficult
to tell whether you are unaware of the scientific data or deliberately
refusing to look at it. You are a science denier at heart.

I consider a lot of data and speculate about possible dynamics. That
is not an "argument." I could make an argument, but I haven't. I'd
probably wind up being wrong. I hate to be wrong, because it suggests
a lapse of good thinking.

You have been claiming that it would all be fine and there was nothing
to worry about for ages.

No. I have been suggesting that this *could* be just another bad
winter cold that was unfortunate to be born in a slow press cycle. I
have made no "claims."

Take a look at this:

https://coronavirus.jhu.edu/map.html

World daily cases peaked 10 days ago and is down. Most european
countries are well past peak, some now below 10% of peak; the ones
that started sooner are down most.

The US case rate is declining and has been basically flat for about 2
weeks now, peaked about April 10. This dropoff, if it continues, will
disappoint some people.

I still think the curves should be scaled by test density, which would
change their shapes radically.

Worry? Personally, I don't worry about much of anything. I guess that
changes my judgements. Fear always overpowers observation and reason.

Somebody should wait a while and do some serious research and write a
book about this event. There is obviously an immense amount of bad
data and "scientific" wrongness and panic circulating now.



That's the way some people design electronics: consider as many
outrageous possibilities as you can, and analyze the consequences of
each. Considering unsanctioned alternatives offends most people.

"Science teaches us to doubt." Or should.

There is a difference between doubting something and going round with
your eyes shut and fingers in your ears impervious to all new data.

That statement is absolutely correct. Doubt should be liberating. It
should break the static friction of what everybody knows. It should
encourage all possible speculations that you can manage, especially
goofy ones. You can sort them out before you etch boards.

I was just talking to The Brat about that. The virus is doing some
harm, but it's also breaking a lot of social static friction. I'm not
about to predict how that is likely to settle out.

I do think that a lot of arguably silly small businesses, goofy
boutiques and bad restaurants, won't come back.

There's an article in today's SF Chronic about small breweries that
will probably fail, or have already failed. They depended on on-site
tap sales or kegs to bars. There were too many small, marginal
breweries competing to make the most bitter hoppy beer possible. Most
can't can their beer, and if they did nobody would pay $8 at Safeway
for a can of beer.

I hope Archer Blonde survives. It's flat delicious.

And Mission Hill Saloon. Jessica pulls us an Archer when she sees us
at the door.



--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Ricky C]

On Wednesday, April 15, 2020 at 2:33:16 PM UTC-4, David Brown wrote:

On 15/04/2020 19:09, Ricky C wrote:
On Wednesday, April 15, 2020 at 5:29:51 AM UTC-4, David Brown wrote:
On 14/04/2020 22:20, Ricky C wrote:
On Tuesday, April 14, 2020 at 6:30:21 AM UTC-4, David Brown wrote:
On 13/04/2020 19:16, Ricky C wrote:
On Monday, April 13, 2020 at 10:25:05 AM UTC-4, David Brown
wrote:
On 12/04/2020 21:28, Ricky C wrote:
On Sunday, April 12, 2020 at 12:27:45 PM UTC-4, David Brown
wrote:
On 12/04/2020 04:52, Ricky C wrote:


snip

I'm going to snip lots of this, because I agree with most of what you
write and the posts are getting ridiculously long.


Parts of China are still on lockdown, and movement into the country is
highly restricted.

Yup, because those regions still have not be rid of the virus. China is being rational and not trying to use a one size fits all approach to dealing with the infection. They've rid Hubei of the disease (or maybe it's only Wuhan, not sure) and have opened up business there, so they are showing it can be done.


China's a big place, and a very diverse place - more so than the USA, I
think. In Western media and thinking, it is often lumped together as
though it were one homogenous place. It makes a lot of sense for them
to treat different parts of their country in different ways here.

It has nothing to do with cultural diversity. It has to do with the difference in infection levels. That and that alone. Wuhan has no new infections and can be opened up. Other areas are still infected at a level that a resurgence is likely if they are opened up, so they aren't yet.

I agree that you can come a long way without a vaccine - if your country
is willing and able to take the necessary steps, and especially if it
starts soon enough (a bit late for that now in the USA).

To late for NYC to prevent ICU overloads, but not for getting rid of the virus. That's what we were talking about. Getting rid of it and maintaining that isolation from the world.


We'll see. (I hope you are right, obviously.)


But without a vaccine - without /knowing/ that the virus is not found
elsewhere, and so will not turn up in your own country - you will always
be on alert, suspicious of travellers and foreigners, monitored and
tracked, and restricted in your way of life.

Yes, we will always be wary of this disease just as we are many, many other diseases. What happens when Ebola breaks out in some part of Africa? We issue travel restrictions and screen anyone suspected of having the disease. For COVID-19 the restrictions will need to be more severe.


One good thing we can hope for out of all this mess is that we (the
world) should be better equipped to handle other disease outbreaks in
the future. Covid-19 is not as lethal as some of the diseases around -
it can be viewed as a practice run. When someone with Ebola comes over
from Africa to the USA, and spreads it to a thousand people in a big
church service or sports event, I hope the experience of Covid-19 means
hospitals will be better equipped and authorities can react faster and
more effectively.

Certainly we will be better prepared to deal with similar infections to COVID-19. Other diseases require a different response. Ebola is not really so hard to contain in a first world country. We have the knowledge, we have the facilities. We had Ebola in the US but it was controlled entirely. It really doesn't spread all that effectively.

It is typical for such viruses to mutate to less lethal forms. The
most effective form of the virus is one that barely makes you sick so
it can be transmitted while people continue their normal lives. So
the virus has selective pressure for that.

Over the long term in a natural environment, that is correct - viruses
and their hosts evolve together to form a stable bias. In the shorter
term, there are no biases - mutations are random. (That does not mean
there are equal chances of a new variant being more or less harmful -
merely that we need to think of the short-term potentials as well as
what will happen over the next few hundred thousand years.)

Mutations are always random. Selection is what determines which mutations spread through the population. Viruses mutate MUCH more rapidly as well as reproduce much more rapidly than animals and plants. So instead of requiring millennia it only requires weeks or months for significant change to take place. There are already many varieties of SARS-CoV-2. They just don't behave much differently... yet. Someone posted a link to a map showing the geographical spread of the mutations.


Evolution towards a low-level endemic infection of a pathogen involves
evolution in the pathogen and the host. It's the evolution of the host
species that takes a very long time here.

There needs to be no evolution in humans for COVID-19 to become less deadly.. That's a false statement.

There is no environmental pressure to select for milder symptoms on the
virus itself, until you are talking about the level of lethality where
the host dies before being able to spread the disease.

Again, not correct. Our social distancing measures have reduced R0 significantly. Factor in that anyone showing symptoms is isolated and you get different R0 values. If R0 is above 1.0 without quarantine and the below 1.0 with quarantine, it clearly will favor the viruses producing fewer symptoms..

As long as each
host spreads the disease to an average of more than one new host before
they die, the pathogen is doing fine. Evolution does not "think ahead"
- it is not guided by long-term planning, such as keeping hosts alive
for the next generation.

Evolution doesn't "think" at all. But is is a result of natural or unnatural selection and is as certain as math.

The intervention of human intelligence changes things a little - the
pathogen does not have to be as deadly before we humans apply measures
to stop the spread. If a strain of SARS-CoV-2 mutated to be
significantly more lethal, then maybe we'd put more effort into stopping
that strain and it would die out - that would be evolutionary pressure
against it.

But milder forms don't have a positive evolutionary pressure - the
lethality of a disease has little effect on its success. The
infectiousness of the disease is what counts for evolution.

Mild doesn't have to be the opposite of lethal. Infectiousness of the virus is a function of severity of the disease in the present environment.

Most mutations in any living organism or virus result in failure - the
organism does not survive, or the virus is not viable. Of the remaining
mutations, most weaken what was already a fairly successful genome. Of
those that still remain, most have little noticeable effect.

You are stating the obvious. What's your point???

There have been a fair number of variations of SARS-CoV-2 found, as
expected. There is little significant difference between them - except
from a split early on, where the mutated version was more severe and
more infectious, and is thus the form that is most common.

I found the opposite info, although once again, tenuous.

'Scientists dubbed the aggressive strain “L type” and the less prevalent version “S type.”'

'“Whereas the L type was more prevalent in the early stages of the outbreak in Wuhan, the frequency of the L type decreased after early January 2020,” they wrote. “Human intervention may have placed more severe selective pressure on the L type, which might be more aggressive and spread more quickly.”'

QED

We never developed a treatment or an effective vaccine for the swine
flu. It is still with us circulating the globe, yet no one seems to
notice.

There /was/ a reasonably effective vaccine against swine flu in 2009,
and it was widely used - like most people in this country, I've had it..
It greatly reduced the spread of the virus.

You have an interesting definition of "effective". There were two vaccines. One providing protection to roughly 50% and the other providing protection to roughly 30%. These are herd immunity vaccines. Individuals aren't protected, but there is enough immunity to lower R0 to less than 1.0.

So your last statement is correct, it reduced the spread of the disease.. Just don't assume you are protected.


That is the way of all vaccines. (Though the protection rate varies.)

50/30% are pretty ineffective numbers for a vaccine.

It is clearly too early to be sure of anything here. The numbers tested
were small, there hasn't been a long time passed since people have been
recovering, and most countries are concentrating on dealing with sick
people rather than testing recovered people.

What we /do/ know is that there are strong indications that immunity
will be partial, incomplete and limited.

No, none of that is true.

That is not the message I am getting from articles I read. But let us
postpone this until we know more.

The articles you are reading either are ignoring the preliminary and tenuous nature of the info or are saying it and you are ignoring it.

(Immunity from past diseases is almost always limited - good enough to
make your chances of reinfection small, but not nearly as complete and
lasting as commonly thought.)

In terms of individuals that may be true, but not so for populations. Think herd immunity.


Herd immunity is a balance between the average individual immunity and
the disease infectivity.

Not really. It's just statistics. A 100% vaccine reduces R0 to 0.0. A less effective vaccine can still reduce R0 below 1.0. That's all that matters. It's just math.

I'd be glad to be wrong here, but is the way it looks to me. Immunity
is almost always limited to some degree, and it would seem that in the
case of Covid-19, it is quite limited. But as you say, the jury is
still out, and we won't know for sure for many months or even years - I
can only talk about indications.

There is virtually no evidence regarding that. Why not wait until there is reasonable research results? It won't take years. We will know soon enough.


It /will/ take years to know how the immunity varies over years. But it
will not take that long to get some estimates, and a lot more information..

Ideally, we need the information quickly - it is critical to being able
to view recovered people as immune, unable to get or spread the
infection (meaning they can work in a hospital with no risk to
themselves, for example).

How can it be "critical"??? What if there is no immunity? What if there is total immunity? One is good, the other sucks. Not knowing is not the issue.

I remember the other two papers now, people seemingly being reinfected. These papers said they could be sure it was actually a reinfection rather than a reemergence of the original infection. Oh, there it is just below, a quote from the paper.


Two links are of the same Korean report of 111 people who tested
positive after having the virus and testing negative.

"Health authorities here have said the virus was highly likely to
have been reactivated, instead of the people being reinfected, as
they tested positive again in a relatively short time after being
released from quarantine."

That is entirely possible - but really, it is just as bad. (Bad in
different ways, but still bad.) The key point (which we don't know at
all) is whether this can result in the person being infectious again
after having recovered from the illness, and whether it can result in
symptomatic problems again.

Not good, but not all that terrible. You seem to think in terms of absolutes. We don't need a perfect barrier. We don't need perfect tests. We need to take measures that will reduce the infection rate to very low levels and keep it there as they have done in China. Once we have that, we can eliminate it from inside the US and deal with any infections that make it into the US by the same method.


I'd rather see an absolute elimination of the disease - but I'll be
happy with a good reduction and containment.

It is the lock downs that will get us to low levels if we are strong enough to follow through.


Agreed.


Again, this will all take time before we have the information. All I am
saying at the moment is that it would be unwise to base strategy on the
idea that people who have had the disease and recovered are immune, and
can't become ill again and can't spread it again.

I'm not sure what you are referring to. I never said anything about it.. The number of immune people is a very small fraction of the population, so it is of no real value.


No, you did not say that - I did not imply that you did. But it has
been the basic strategy for some countries' initial response to the
disease (such as the UK).

Yeah, well, that didn't last too long. Voters decided they didn't want a ticket in the COVID lottery.

(And this could also be a problem for vaccines - it may be hard to get
long-term immunity from a vaccine. For some diseases, this is solved by
having several vaccines over the course of months or a couple of years,
for others you need boosters every 5 or 10 years.)

Vaccines don't have to work the way natural immunity does. Vaccines can be targeted to specific antigens that we know and understand and even extend to other diseases. We also know something about which antigens can mutate and which can't. If the antigen is essential to the function of the virus it can't both mutate and produce a viable virus.


Correct. But to develop (or pick) a good vaccine, it is useful to know
the details of the natural immune response - what the antibodies target,
and how well that immunity lasts. Then we can try and provoke a better
immune response.

We already know the antigen for the COVID-19 antibodies. That's how we produce an antibody test. We understand the human immune response. Producing a vaccine is much more complex than that.

The other two links are about an not peer reviewed study finding
"low" levels of antibodies in previously infected individuals with
zero clinical indication of reinfection. That is doubly lame.


It is all preliminary indications - I am not claiming anything else.

Not sure what that means. Above you said, "Immunity is almost always limited to some degree, and it would seem that in the case of Covid-19, it is quite limited." and other, similar statements. I think you are giving these reports far too much credence. You need to understand what Larkin doesn't, that one swallow does not a summer make. Scientific research works by lots of small movements, some forward, some sideways, some backwards. But the net motion, not unlike evolution, is forward. Just don't pay too much attention to the Brownian motion while waiting to see the larger movements..


I am entirely aware of that.

The picture I am seeing at the moment, from a number of things I have
read, is that immunity from Covid-19 is likely to be limited. I may be
interpreting incorrectly, I may be putting too much weight on particular
sources, I may be too pessimistic here. It is too early to be sure, and
I will update my picture as time goes by.

So far all the references you have provided are very weak in supporting this idea. They even say that in the articles.

You do realize the Internet is a giant echo chamber where one source can say something and it echos around for a long time? How many of those sources are from the same data?

I am not recommending we do nothing until a vaccine is available! I
agree with all your recommendations and strategies - but I don't think
we will get out of this mess properly until we have a vaccine as well.

We will see. In the mean time we need to take rational actions and not rush into anything as we seem to want to do to save the economy. Who knows, maybe it's a lose-lose scenario where there is no happy middle and we are doomed to both be ravished by this disease and crash the economy.


Agreed.

I thinking we have covered everything there is to cover on this topic.


Fair enough - even with the snipping I made, the post is still long.

I am sure we will pick it up again when we know more.

Ok....

--

Rick C.
+--+- Get 1,000 miles of free Supercharging
+--+- Tesla referral code - https://ts.la/richard11209

 

whit3rd <whit3rd@gmail.com> wrote in
news:b65dfec7-f689-42cc-b05a-09c210a17e44@googlegroups.com:

On Wednesday, April 15, 2020 at 8:00:08 AM UTC-7,
jla...@highlandsniptechnology.com wrote:

I have been suggesting that this *could* be just another bad
winter cold that was unfortunate to be born in a slow press
cycle. I have made no "claims."

The arrogant dismissal is clear, the testable assertions are not.

The virus is novel, so "another" is correct.

The 'winter' assertion would be contrary to the Australian
experience; incorrect.

A 'cold' doesn't have the same symptoms (which is how, in China,
the disease was discovered) nor the same cause (a virus not
previously known in humans), but we've folded many other viruses
into that catch-all. Spin, this assertion is, and sloppy
nomenclature, and... rejected because it's MY language too, and I
need clarity. I also am defensive of SI units...

'Bad', while also not testable because not quantified, can stand.

There are LOTS of slow press cycles, they don't become pandemics.

I still think the curves should be scaled by test density, which
would change their shapes radically.

But, science doesn't need those local-condition-dependent curves.
The disease is being fought in ways that are uneconomic, we need
to understand other-than-lockdown treatments, and
curve-description doesn't help that. There's no treatment
protocol or vaccine in that information. The publication and
discussion of curves IS a slow-press-cycle effect.

I rememeber they trained a few dogs and they could spot a cancer
patient by smell.

Maybe they could train a few dogs for NYC that can differentiate
COVID19. Now THAT would be cool. If a dog can sniff it, maybe we
could build an electronic MEMS sniffer or such.