Coronavirus

[dfwatt]

Bloomberg - Are you a robot?

Reactivation casts doubt on whether acquired immunity can be relied on. This does not look good for the herd immunity enthusiasts. There is still much that needs to be learned about the longer term behavior of Covid19.

There's simply not enough data in that report to conclude much of anything. Most critical would be whether "reinfection" is taking place within a one-month window from the first positive PCR test. A lot of ID and Immunology folks believe that open quotes reinfection close quotes is actually simply fluctuations at the tail end of the process and not reinfection but actually failure to terminate the infection in the first place. The other thing worth remembering is that if IGG antibodies are mature and at an adequate level it would be literally a one-off case of an illness in which that did not confer significant protection. This of course applies mainly to viruses that do not mutate quickly and covid-19 appears to be in that group.

The other issue of course is whether reinfection takes place in the context of immunocompromise from steroids, antibiotics, or severe sleep deprivation or other known immunosuppressive issues, and again we know that in this context immune surveillance and rapid ramp-up of the Adaptive branch of the immune system can be impaired, in the context of defective recognition of re-presentation of a pathogen. In other words immunosuppressed people can show sluggish or perhaps even defective ramp-up of a defense against pathogen that is recognized and properly 'coded' in immune memory by T cells and antibodies. We see this repeatedly in older folks where there's a reappearance of shingles after administration of antibiotics, infection with another pathogen, or other challenges in vulnerable and more elderly cohorts.

Short form of a long story is I really don't think we have any solid evidence to believe that reinfection is going to be a significant threat inside of six months anyway. We don't know that for sure, but again, based on similar diseases, and again assuming that there is adequate IGG for the pathogen, I think we have to assume the more optimistic position holds true (essentially as the 'default' position) until proven otherwise.

 

[SageBrush]

Those agree of course. The total number of people currently hospitalized is equal to the sum of net hospitalizations. The net daily hospitalizations is equal to new hospitalizations minus people who are discharged and people who die.

Read the second half of my post

 

[bkp_duke]

I still can't get around the fact that no one gave a crap about the 60K mostly old+sick people who died from the flu in 2017-2018. Yet we've shut down the world over this event. Yeah, I know all about the "overloaded hospitals", etc.

I keep seeing this comparison to the flu . . . but does anyone realize those flu deaths are with ZERO social distancing?

SARS-CoV2 is on track in 2-3 months eclipse total yearly influenza deaths, and that is WITH social distancing.

Let's all let that sink in for a few minutes, OK?

 

[SageBrush]

The limited data from this study was helpful to the authors. Instead of guessing at the extent of infection and mortality rates in the community they have better data on which to base recommendations for how best to respond to the pandemic.

Their data is not much different than my saying
"Today, there are 35k new cases, and a total of 400k cases"

What does that tell us ? Just about nothing.

We should be seeing a flurry of serological reports coming out in the next few weeks. Collectively, they should give us a much better understanding of infectiousness and mortality.

Nah.
I think the only measure the serology will give (with a LOT of uncertainty) is what fraction of the infections are getting RNA testing. For that locale, anyway.

 

[dhanson865]

posted with the caption "well, thank goodness the virus can't move sideways"

 

[blckdmp]

My perception of trying to force the economy to "normal" while a pandemic is still raging.

 

[EinSV]

There data is not much different than my saying
"Today, there are 35k new cases, and a total of 400k cases"

What does that tell us ? Just about nothing.

The scientists who conducted the study were comfortable enough with the surprisingly low mortality rate and the effectiveness of hygiene efforts that they recommended lifting stay at home restrictions as part of their four step protocol. They don't seem to share the skepticism of a few members here for antibody testing, and in fact the Robert Koch Institute in Germany is planning to ramp up more antibody testing in the coming weeks. Germany’s 'Wuhan' has 15 per cent infection rate and low death toll

I think the only measure the serology will give (with a LOT of uncertainty) is what fraction of the infections are getting RNA testing. For that locale, anyway.

Every statement I have seen from experts in the field is that they view antibody testing as the key to understanding infectiousness, mortality rates and the extent the disease has spread.

Perhaps they are wrong and the non-experts on this forum are right, but I'll have to go with the experts on this one.

 

[Daniel in SD]

The scientists who conducted the study were comfortable enough with the surprisingly low mortality rate and the effectiveness of hygiene efforts that they recommended lifting stay at home restrictions as part of their four step protocol. They don't seem to share the skepticism of a few members here for antibody testing, and in fact the Robert Koch Institute in Germany is planning to ramp up more antibody testing in the coming weeks. Germany’s 'Wuhan' has 15 per cent infection rate and low death toll



Every statement I have seen from experts in the field is that they view antibody testing as the key to understanding infectiousness, mortality rates and the extent the disease has spread.

Perhaps they are wrong and the non-experts on this forum are right, but I'll have to go with the experts on this one.

I'm a little confused by this.
0.37% in a single region of Germany does not disagree with my 0.5%-2% prior for IFR. Different populations will have different IFRs.
I am a little bit confused on their data. How many people in that town have died or are critically will with COVID-19? How did they go about ensuring that the sample was random?
It doesn't seem like you can extrapolate from a single town to a whole region, especially if you've put in place restrictions on freedom of movement.

 

[MXLRplus]

Something else to consider when thinking about people laying themselves off voluntarily for 3+ months. Most Tesla's subtiers do not pay $25/hr so they are better off financially by quitting.

 

[EVNow]

Every statement I have seen from experts in the field is that they view antibody testing as the key to understanding infectiousness, mortality rates and the extent the disease has spread.

When the accuracy is only +/- 5%, you don't know what the real immune population if the result is 3%.

 

[HG Wells]

Highlands NC has police checking entry into the city.

Stay at home | The Highlander, Highlands, North Carolina

 

[SageBrush]

I don't think so. Note that I posted the same slide from a day later and they changed the title to "Increase in total patients hospitalized"

He says that the total in the state is about the same. I think this is from Apr 6

 

[MXLRplus]

So, would you say Boris Johnson had less than 1% chance of death when admitted to ICU ?

Also, its not just fatality that matters. Hospitalization itself is a major risk in itself. I don't want to get the virus and end up in a hospital with pneumonia no more than I want to get into an accident and end up in a hospital with broken bones.

Yet you drive a car, which is the #1 cause of adult broken bones. Why is that? Are you fearless or a cyborg?

 

[EVNow]

Short form of a long story is I really don't think we have any solid evidence to believe that reinfection is going to be a significant threat inside of six months anyway. We don't know that for sure, but again, based on similar diseases, and again assuming that there is adequate IGG for the pathogen, I think we have to assume the more optimistic position holds true (essentially as the 'default' position) until proven otherwise.

This has been getting some attention - and could be worrying.

Eric Feigl-Ding on Twitter

This is very worrisome. Among recovered former #COVID19 cases, “nearly a third had unexpectedly low levels of antibodies. In some cases, antibodies could not be detected at all.”
​

Low antibody levels raise questions about coronavirus reinfection risk

And even more weird ...

“The team also found that antibody levels rose with age, with people in the 60-85 age group displaying more than three times the amount of antibodies as people in the 15-39 age group.”
​

ps :

 

[MP3Mike]

Something else to consider when thinking about people laying themselves off voluntarily for 3+ months. Most Tesla's subtiers do not pay $25/hr so they are better off financially by quitting.

Only if they are positive that they will get rehired. Their company may replace them while they are gone and then not have a position available to rehire them later. (Or may not want to rehire them.)

 

[Daniel in SD]

And then look at the fraction of hospitalized compared to total positive tests, which we know to be ~ 10%
IIRC total positive tests are ~ 140k, so somewhere in the range of 14k hospital admissions

The daily number of people who test positive is now flat. That would imply that the number of new people being hospitalized per day is relatively flat (~10k per day). If this continues the number of people currently hospitalized will flatten out. In order for it to drop the number of people testing positive per day will have to drop (assuming testing criteria remains the same).
Workbook: NYS-COVID19-Tracker

 

[SageBrush]

Every statement I have seen from experts in the field is that they view antibody testing as the key to understanding infectiousness, mortality rates and the extent the disease has spread.

Eventually, yes.
During the growth phase of the epidemic -- no

 

[EinSV]

When the accuracy is only +/- 5%, you don't know what the real immune population if the result is 3%.

Serology tests can have much better specificity than that.

In the German test, for example, they reported that specificity was greater than 99%, and they estimated 15% of the population infected. And from the press reports, 15% was considered conservative.

Since PCR testing missed the vast majority of cases, I can see why scientists prefer serology tests to assess morbidity and mortality rates, infectiousness, etc.

Per Google translate:

Preliminary result: An existing immunity of approx. 14% (anti-SARS-CoV2 IgG positive, method specificity>, 99%) was determined. About 2% of the people had a current SARS-CoV-2 infection detected using the PCR method. The overall infection rate (current infection or already gone through) was approx. 15%. The mortality rate (case fatality rate) based on the total number of infected people in the community of Gangelt is approx. 0.37% with the preliminary data from this study. The lethality currently calculated by the Johns-Hopkins University in Germany is 1.98% and is 5 times higher. Mortality based on the total population in Gangelt is currently 0.15%

https://www.land.nrw/sites/default/...ischenergebnis_covid19_case_study_gangelt.pdf

 

[EVNow]

Serology tests can have much better specificity than that.

Zachary Binney, PhD on Twitter

The FDA has approved the first antibody test for COVID-19, from Cellex. It theoretically tells you if you've had it & are, as far as we know, immune for some time. Sensitivity is 93.8%, specificity 95.6%. Sounds great, right?

If only a small % have actually had COVID-19 (our best guess now) a "positive" antibody test isn't that likely to mean you're immune. If only 4.5% of U.S. has had COVID-19, + test only means ~50% chance you really had it. With lots of uninfected, lots of false +s. (2/6)​

 

[SageBrush]

The daily number of people who test positive is now flat.

That is correct, but it does not help you resolve the question of whether 'hospitalized' means net new beds occupied by Covid patients or new admissions.

Admissions today are infections from 7 - 10 days ago;
Net bed change = admissions less discharges.
-- discharges are deaths and recoveries.

Discharges on Apr 7 are ~ 1200
If ~ 600 are net bed change,
Then admissions are ~ 1800

Positive tests on Apr 2-4 are ~ 7500 a day
Your interp implies that ~ 1/4 cases are being admitted.