Preliminary test results suggest 21% of NYC residents have Covid antibodies • Hacker News Board

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#71

Post by zucker42 » Thu, Apr 23, 2020, 6:22 PM UTC

ccleve wrote: post #17

This study doesn't appear to suffer from the same methodology problems as the Stanford study of a few days ago. In that study, they recruited people through Facebook, and reported an infection rate that was low enough that it could have been caused by false positives. Here, it's closer to a random sample, but more importantly it shows really high rates. Those rates overwhelm any error due to false positives. Also, it…

Is there a write-up for this study? Or anywhere with data/methodology released?

Also, is this particularly good news? Using the raw numbers from the headline and the deaths from here https://www1.nyc.gov/site/doh/covid/covid-19-data.page we can make coarse fatality rate estimates. I assume population of NYC is 8,400,000.

10290 / (.212 * 8.4e6) = 0.6%

Including probable deaths (which makes the death count line up more closely with excess deaths)

15411 / (.212 * 8.4e6) = 0.9%.

So it seems consistent with a IFR of 0.5%-1%. However, this doesn't account for the lag between antibody presence and death. Also, we don't know what bias sampling from grocery stores introduces, it could affect the results in either direction. Hopefully, New York releases a paper so we can get more accurate estimates.

It's good to see a prevalence study with presumably less flaws.

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#72

Post by daxfohl » Thu, Apr 23, 2020, 6:23 PM UTC

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

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

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

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#73

Post by DeonPenny » Thu, Apr 23, 2020, 6:24 PM UTC

vkou wrote: post #24

If this study is accurate, and is not just working on garbage data, and if these antibodies actually mean long-term immunity, this means one of two things: 1. If the lockdown is lifted, we will see another ~60,000 to 100,000 deaths in NYC, before it will hit herd immunity. 2. Or, the lockdown will continue. The accuracy of antibody studies has been called into doubt, and as far as I know, nobody has ever followed up…

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

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#74

Post by jdm2212 » Thu, Apr 23, 2020, 6:27 PM UTC

glofish wrote: post #60

cma wrote: post #51

Earlier quoted context omitted.

Exaggerated in that the California study predicted a flu like IFR (Ioannidis, one of the authors, has been pushing that as his pet theory for over a month). This shows it is more likely several times that.

it doesn't contradic Ioannidis at all. He might be right in the end, and that would be an incredibly bitter pill to many. We are getting closer and closer to the flu fatality rate. from 5% to 3%, then 1% now 0.5% - smart money (and common sense) would bet that the rate will continue to drop, I would expect that people living in healthier environment than NYC will fare even better. No way NYC IFR is the upper bound fo…

NYC is a younger, healthier city than the national average. NYC also has one of the best medical systems not just in America, but in the world.

Roughly 0.2% of everyone in NYC has already died of COVID-19. So 0.2% is pretty close to a hard lower bound on the IFR for COVID-19.

And I don't think anyone serious suggests every NYC resident has had COVID. I don't think anyone seriously suggests even half of NYC has had COVID.

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#75

Post by tunesmith » Thu, Apr 23, 2020, 6:28 PM UTC

ccleve wrote: post #17

This study doesn't appear to suffer from the same methodology problems as the Stanford study of a few days ago. In that study, they recruited people through Facebook, and reported an infection rate that was low enough that it could have been caused by false positives. Here, it's closer to a random sample, but more importantly it shows really high rates. Those rates overwhelm any error due to false positives. Also, it…

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

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

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

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

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#76

Post by lukasm » Thu, Apr 23, 2020, 6:28 PM UTC

cm2187 wrote: post #2

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

Yes, but the age is a 10x factor, os CFR would be much different in Nigeria (average age is about 19) and Italy (average age 45). We have two good petri dishes:

USS Theodore Roosevelt - 600 cases out of 4800. 5 sick, one dead (41 years old). which means hospitalisation is at 0.83% and CFR is 0.016% (1% dead or in hospital). Not idea what is the average age, probably around 30-35.

Diamond Princess: 700 of 3711. CFR 1.1%, average age around 50.

What worries me the most though is potential mutations and death rates when you are infected with Covid-19 and flu at the same time (or other pathogens).

https://www.reuters.com/article/us-health-coronavirus-usa-mi...

https://www.nature.com/articles/d41586-020-00885-w?utm_sourc...

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#77

Post by tunesmith » Thu, Apr 23, 2020, 6:33 PM UTC

DeonPenny wrote: post #73

vkou wrote: post #24

If this study is accurate, and is not just working on garbage data, and if these antibodies actually mean long-term immunity, this means one of two things: 1. If the lockdown is lifted, we will see another ~60,000 to 100,000 deaths in NYC, before it will hit herd immunity. 2. Or, the lockdown will continue. The accuracy of antibody studies has been called into doubt, and as far as I know, nobody has ever followed up…

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

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

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#78

Post by votepaunchy » Thu, Apr 23, 2020, 6:33 PM UTC

nullc wrote: post #50

grey-area wrote: post #40

Earlier quoted context omitted.

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

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

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

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#79

Post by [deleted] » Thu, Apr 23, 2020, 6:35 PM UTC

SpicyLemonZest wrote: post #42

caiobegotti wrote: post #37

Earlier quoted context omitted.

https://en.wikipedia.org/wiki/Herd_immunity#Mechanics

Although it should be noted that incomplete herd immunity will still help, by reducing the number of other containment measures which must be taken.

[deleted]

Re: Preliminary test results suggest 21% of NYC residents have Covid antibodies

#80

Post by glofish » Thu, Apr 23, 2020, 6:35 PM UTC

jdm2212 wrote: post #74

glofish wrote: post #60

Earlier quoted context omitted.

it doesn't contradic Ioannidis at all. He might be right in the end, and that would be an incredibly bitter pill to many. We are getting closer and closer to the flu fatality rate. from 5% to 3%, then 1% now 0.5% - smart money (and common sense) would bet that the rate will continue to drop, I would expect that people living in healthier environment than NYC will fare even better. No way NYC IFR is the upper bound fo…

NYC is a younger, healthier city than the national average. NYC also has one of the best medical systems not just in America, but in the world. Roughly 0.2% of everyone in NYC has already died of COVID-19. So 0.2% is pretty close to a hard lower bound on the IFR for COVID-19. And I don't think anyone serious suggests every NYC resident has had COVID. I don't think anyone seriously suggests even half of NYC has had CO…

All I am saying people there breath the NYC air every single day. Can't possibly be good for them, especially in the light of some chronic pulmonary inflammation induced deaths.

The point on the lower bound of 0.2% is informative. I did not know that.