New York antibody study results

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New York antibody study results - magnus - 04-23-2020

Cuomo just posted infection projections based on NY's antibody study.

[Tweet]https://twitter.com/NYGovCuomo/status/1253352837255438338?s=20[/tweet]

21% in NYC.

I don't have a source for the actual study.

RE: New York antibody study results - BostonCard - 04-23-2020

Interesting data. Would like to see the methodology used.

This would suggest that the confirmed infection rate is off by a factor of 10x, and the the IFR is about 0.8% (pending outcomes of sick patients who haven't died yet).

BC

RE: New York antibody study results - burger - 04-23-2020

Assuming that NYC's test has accuracy similar to the Stanford test, false positives should not be a major issue for the NYC and NYC-area results. It could matter for the statewide results.

But we'll need more information to know how good the sampling was. I saw that they sampled at grocery store and big box store parking lots. That's potentially more random than calling people or facebook ads, but the devil is always in the details.

For future studies like this, I think one way around the self-selection problem would be to pay people to participate. If you give everyone an incentive to give blood, maybe you can reduce motivation to get tested as a factor. I bet China could do a great study--just have the blood extraction people show up at everyone's door with a few police officers. 100% participation guaranteed!

RE: New York antibody study results - 2006alum - 04-23-2020

Definitely want to see the dataset and estimates for that, but 20% for NYC fits my impressionistic sense and largely maps onto the seeming consensus that the IFR is somewhere in the .5-1% range.

That said, there's definitely the risk of sampling bias insofar as those who go out to grocery stores and big box stores are likely to have had more exposure opportunities in general. My elderly relatives have avoided all shopping for the past 5-6 weeks and relied on younger folks (like me) and grocery delivery services to get their essentials, and none of those (unexposed) folks would show up in their sample.

The other thing I want to note, as I've said elsewhere, is that I think we need to seriously question whether the denominator of the NYC population is anywhere near the census figure of 8.4 million people. Probably half the people I know whose permanent residence is NYC are upstate, on Long Island, or out of state, so my guess is that we're talking more like 6 million people actively living and working in the five boroughs right now. That doesn't change the antibody prevalence right now, but it does mean "when we get back to normal" and those couple million of people return, there will be a substantial portion of the herd who never got immunity (assuming such immunity meaningfully exists).

I'd really like to see Google or Apple's cell phone GPS data for NYC. I have to imagine there's a brobdingnagian reduction in the number of cell tower pings as compared to this time last year, and not all of that is tourism and regional commuters.

---

Meanwhile, can anyone understand how Sweden's chief epidemiologist can substantiate his claim of near-herd immunity in Stockholm? What are they doing differently that enables them to have a higher prevalence rate than NYC with a much, much lower IFR?

RE: New York antibody study results - Farm93 - 04-23-2020

(04-23-2020, 10:31 AM)burger Wrote: Assuming that NYC's test has accuracy similar to the Stanford test, false positives should not be a major issue for the NYC and NYC-area results. It could matter for the statewide results.

But we'll need more information to know how good the sampling was. I saw that they sampled at grocery store and big box store parking lots. That's potentially more random than calling people or facebook ads, but the devil is always in the details.

For future studies like this, I think one way around the self-selection problem would be to pay people to participate. If you give everyone an incentive to give blood, maybe you can reduce motivation to get tested as a factor. I bet China could do a great study--just have the blood extraction people show up at everyone's door with a few police officers. 100% participation guaranteed!

Governor Cuomo explained the methodology and many of the limitations, and didn't oversell the results. He also stressed some of the groups he hopes to analyze in greater detail in the next few weeks.

I watch the NY briefings and just wish the Federal ones had a similar format.

Today's new wrinkle was the sampling of New Yorkers for antibodies.
21% of NYC participants had antibodies.
Just less than 4% of the upstate residents had antibodies.

NYC probably is the upper bound rate for antibodies nationally.
Upstate NY has had the same stay at home restrictions as NYC, so at this point upstate NY could be close to the rate in many mid-sized states.

I would imagine that Los Angeles is probably in the low teens today, while most of the rest of the CA might be down in the 3-5% range. I need to imagine and guess because for some inexplicable reason the federal government has yet to do anything like this NY effort nationally.

Using a ~3% rate nationally would imply ~10 million have antibodies and the fatality rate would 0.5% WITH the vast majority of the USA working diligently to slow the infection rate.

The NY data really makes me want to get an antibody test. In early March for the first time in years I had a fever and other flu-like symptoms, for 2 days, after spending an evening in a meeting next to someone that had a persistent cough for weeks after visiting China in December. At the time I was so worried he had COVID19. Now I almost hope he did have COVID19.

RE: New York antibody study results - Snorlax94 - 04-23-2020

(04-23-2020, 11:01 AM)Farm93 Wrote: The NY data really makes me want to get an antibody test. In early March for the first time in years I had a fever and other flu-like symptoms, for 2 days, after spending an evening in a meeting next to someone that had a persistent cough for weeks after visiting China in December. At the time I was so worried he had COVID19. Now I almost hope he did have COVID19.

Like you, I’ve combed through memories to see whether there is any way I might have antibodies, but for me it feels very unlikely because I just can’t get the timeframes to line up (I visited Vancouver BC for Christmas, but it wouldn’t start getting cases for another two months...) While I hope you do have immunity, if your co-worker was in China in *December*, and he sat next to you in *March*, that would be an awfully long cough. If people were walking around feeling ok, coughing and contagious for 3-4 months, the Ro would be a gazillion.

RE: New York antibody study results - BostonCard - 04-23-2020

(04-23-2020, 10:37 AM)2006alum Wrote: Meanwhile, can anyone understand how Sweden's chief epidemiologist can substantiate his claim of near-herd immunity in Stockholm? What are they doing differently that enables them to have a higher prevalence rate than NYC with a much, much lower IFR?

Per the article:

Quote:Tegnell said sampling and modeling data indicated that 20% of Stockholm’s population is already immune to the virus, and that “in a few weeks’ time we might reach herd immunity and we believe that is why we’re seeing a slow decline in cases, in spite of sampling (testing for the coronavirus) more and more.”

20% immunity is comparable to what New York City has seen so far. The Stockholm region has a population of about 2 million, so if the number is correct, 400,000 have been infected. Total deaths in the region have been 1128 for an IFR of 0.03. That's plausible, but perhaps a bit lower than one might expect.

BC

RE: New York antibody study results - dabigv13 - 04-23-2020

I had a fever and cough in mid February along with my wife. Both of us are ENTs, so high likelihood of exposure if it was in community. Still though, I suspect my odds of being antibody positive are less than 1 in 20. There just was not enough community spread in mid February, and plain old flu or other URIs were much more prevalent. I am still curious where NYC got their antibodies. So many of the commercially available tests seem to be questionable in both their specificity and sensitivity.

RE: New York antibody study results - magnus - 04-23-2020

(04-23-2020, 11:01 AM)Farm93 Wrote: 21% of NYC participants had antibodies.
Just less than 4% of the upstate residents had antibodies.

NYC probably is the upper bound rate for antibodies nationally.
Upstate NY has had the same stay at home restrictions as NYC, so at this point upstate NY could be close to the rate in many mid-sized states.

I would imagine that Los Angeles is probably in the low teens today, while most of the rest of the CA might be down in the 3-5% range. I need to imagine and guess because for some inexplicable reason the federal government has yet to do anything like this NY effort nationally.

Using a ~3% rate nationally would imply ~10 million have antibodies and the fatality rate would 0.5% WITH the vast majority of the USA working diligently to slow the infection rate.

I would think that upstate NY's number is at least somewhat influenced by proximity/interaction with NYC residents. So even 3% might be too high to use nationally.

RE: New York antibody study results - Farm93 - 04-23-2020

(04-23-2020, 02:54 PM)magnus Wrote: I would think that upstate NY's number is at least somewhat influenced by proximity/interaction with NYC residents. So even 3% might be too high to use nationally.

Not really... the suburban counties near NYC were in their own category.

Those in upstate NY really are more like Vermont than NYC.

There might be a bit of NYC residents using winter cabins or going to ski resorts that would cause spread to those areas, but probably no more than the amount of spread caused by LGA or JFK to ATL or DFW.

The upstate NY that was in the Upstate NY is likely largely comparable to TN, KY, the Alabama-like parts of PA, etc.

Again, sure would be nice for the Federal government to start widespread antibody testing or even sampling of the population to get a sense for the true size of that denominator.

Why?
If 10 or 15% of the USA population has antibodies the stock market would soar so quickly and people would learn the virus is not really as deadly as we suspect right now.
For our stock market and economy obsessed POTUS testing just 3,000 US citizens could do more than 20 or 30 more daily briefings.

It seems like a better miracle play than dreaming about a miracle drug or the COVID19 vanishing from the planet before the end of April.

RE: New York antibody study results - DenverCard - 04-23-2020

Doubt about the accuracy of the Santa Clara antibody/prevalence study is being made irrelevant by studies with the same goal that have involved pregnant women, prisoners, Sweden, and now NY that suggest a very high number of asymptomatic patients with the virus. Does this not spell doom to the effort to have people shelter in place, especially when combined with a) the economic pressure to open up society again and b) social isolation fatigue that is taking hold, at least per my personal observations (and feelings, even as one who is uncommonly apprehensive about contracting the virus)?

With a high prevalence of asymptomatic carriers, any attempt at contact tracing is doomed. Already it seems that the virus is everywhere, and that it's only a question of when, rather than if, a person contracts it, unless he/she is a super-isolater.

With indications that a game-changing treatment (e.g. chloroquine, remdesivir) is unlikely, and the long horizon for a vaccine, there is less benefit to the individual to deferring -- so to speak -- his/her infection for a time when treatment options are likely to be significantly better.

There remains the benefit to society of social isolation, insofar as it can help prevent hospitals from becoming overwhelmed, but that is going to be an increasingly hard sell as summer approaches, especially if the estimated IRF becomes less.

RE: New York antibody study results - 2006alum - 04-23-2020

(04-23-2020, 03:52 PM)DenverCard Wrote: Doubt about the accuracy of the Santa Clara antibody/prevalence study is being made irrelevant by studies with the same goal that have involved pregnant women, prisoners, Sweden, and now NY that suggest a very high number of asymptomatic patients with the virus. Does this not spell doom to the effort to have people shelter in place, especially when combined with a) the economic pressure to open up society again and b) social isolation fatigue that is taking hold, at least per my personal observations (and feelings, even as one who is uncommonly apprehensive about contracting the virus)?

With a high prevalence of asymptomatic carriers, any attempt at contact tracing is doomed. Already it seems that the virus is everywhere, and that it's only a question of when, rather than if, a person contracts it, unless he/she is a super-isolater.

With indications that a game-changing treatment (e.g. chloroquine, remdesivir) is unlikely, and the long horizon for a vaccine, there is less benefit to the individual to deferring -- so to speak -- his/her infection for a time when treatment options are likely to be significantly better.

There remains the benefit to society of social isolation, insofar as it can help prevent hospitals from becoming overwhelmed, but that is going to be an increasingly hard sell as summer approaches, especially if the estimated IRF becomes less.

I must be missing something -- epidemiologists are using the NY data to infer a close to 1% IFR, whereas the Santa Clara study famously estimated an IFR of between .12-.2%. Those are worlds apart. I still think it's way too soon to think we known all we'll know about transmission methods, IFR, and potential treatments.

And more to the point, the reason why we are flattening the curve is so that hospitals don't get overwhelmed the way they did in NYC. If the NY study has accurately estimated the prevalence, that means 4/5ths of NYC has not yet been infected, so NYC is hardly a case study in why shelter in place has been an overreaction.

RE: New York antibody study results - Griffins78 - 04-23-2020

Also relevant is that even with the presence of anti-bodies, we don't know if that confers immunity and for how long and if they are no longer infectious.

RE: New York antibody study results - DenverCard - 04-23-2020

I realize that in my post above, I did not express what I meant to address, and that is the issue of virus containment efforts and how I fear it is a losing game. Previously, in addition to the benefits of flattening the curve to preserve the capacity of ICUs and hospitals more generally, available ventilators, etc., there were the other goals of sheltering in place mentioned in my earlier post. But recent developments threaten those other benefits. If the prevalence of the virus is already quite high, staying at home to allow a more surgical contact tracing strategy is not tenable. Isolating oneself in the hopes of effective drugs to be found and approved in the not-too-distant future may not bear fruit. And motivation by many to do the hard work of social isolation has to be waning, even as one is constantly exposed to ever-present accounts of suffering that are hard to bear.

The impetus for my previous post and another recent one was a recent visit to my elderly parents (80+) who have the added risk created by the fact that my middle-aged brother lives with them and works out of the home. I found it harder to make the case to my mother to avoid trips to the grocery store, and to try to modify the situation involving my brother for my parents' protection. Instead, it seems that the tide of the virus is soon to wash over all of us despite our efforts to contain it, and that one can only hope that his or her immune system is neither under- nor over-reactive when faced with fighting it off.

This board is a fantastic source of de facto psychotherapy, and I guess I'm now looking for more. The good news is that....

RE: New York antibody study results - Farm93 - 04-23-2020

(04-23-2020, 11:13 AM)Snorlax94 Wrote:
(04-23-2020, 11:01 AM)Farm93 Wrote: The NY data really makes me want to get an antibody test. In early March for the first time in years I had a fever and other flu-like symptoms, for 2 days, after spending an evening in a meeting next to someone that had a persistent cough for weeks after visiting China in December. At the time I was so worried he had COVID19. Now I almost hope he did have COVID19.
Like you, I’ve combed through memories to see whether there is any way I might have antibodies, but for me it feels very unlikely because I just can’t get the timeframes to line up (I visited Vancouver BC for Christmas, but it wouldn’t start getting cases for another two months...) While I hope you do have immunity, if your co-worker was in China in *December*, and he sat next to you in *March*, that would be an awfully long cough. If people were walking around feeling ok, coughing and contagious for 3-4 months, the Ro would be a gazillion.

Yeah, I agree the fit is not perfect, but I don't think he had the cough that whole time. I believe he went to China to visit a manufacturing plant several times a year. We are in the same youth sports board, so I don't really know his work itineraries in that way. Could have been December or January. At the time I was livid that this guy was hacking and dry coughing after recent trips from Asia at the very time we were talking about what to do if COVID19 impacts our program.

Fast forward 4 days after that meeting and I was really worried. On that day I was late getting the waste bins to the street because I was trying to sleep off my mini-health issue. After going DOWN the stairs I was so winded you'd have thought I was a 3 pack a day smoker. Never had that happen in my life.

Probably just a terrible, unrelated illness, but if I could acquire an antibody test at home I would definitely take the test with the hope that I now have COVID19 antibodies running around.

Since March I only went in one supermarket in mid-March and have been using curbside pick-up services since. If I wasn't exposed to COVID19 at that time I probably lack the antibodies.

RE: New York antibody study results - dabigv13 - 04-23-2020

The good news is that mitigation works. Social distancing has meaningfully slowed the disease. But the reason we can't just let the virus wash over us is because then you get NYC level medical system collapse, and they would as well if they relaxed too much because they're not close to herd immunity.

If you mitigate for long enough that community transmission is near zero, then you will have a few weeks of lead time to shut down localized areas if numbers go up after you reopen. Track and trace with saliva testing and cell phone GPS tracking. Its feasible. Korea has been doing it.

RE: New York antibody study results - 2006alum - 04-23-2020

(04-23-2020, 05:12 PM)DenverCard Wrote: The impetus for my previous post and another recent one was a recent visit to my elderly parents (80+) who have the added risk created by the fact that my middle-aged brother lives with them and works out of the home. I found it harder to make the case to my mother to avoid trips to the grocery store, and to try to modify the situation involving my brother for my parents' protection. Instead, it seems that the tide of the virus is soon to wash over all of us despite our efforts to contain it, and that one can only hope that his or her immune system is neither under- nor over-reactive when faced with fighting it off.
This board is a fantastic source of de facto psychotherapy, and I guess I'm now looking for more. The good news is that....

I'm very sorry to hear that, but I am still uncertain what it is that is making your case "harder" for your mother to avoid trips to the grocery store. The slow progress on a vaccine? The failure to find a game changing treatment? I guess it seems like, if anything, the bad news about the progress of SARS-COV-2 would suggest you have a stronger case for her to stay in, not a weaker one?

RE: New York antibody study results - dabigv13 - 04-23-2020

In case anyone was wondering, the antibodies for this test were apparently developed by New York State labs, and has received federal approval. Feel better about that than random noname Chinese companies.

https://www.nytimes.com/2020/04/23/nyregion/coronavirus-antibodies-test-ny.amp.html

RE: New York antibody study results - stupac2 - 04-23-2020

(04-23-2020, 05:40 PM)2006alum Wrote:
(04-23-2020, 05:12 PM)DenverCard Wrote: The impetus for my previous post and another recent one was a recent visit to my elderly parents (80+) who have the added risk created by the fact that my middle-aged brother lives with them and works out of the home. I found it harder to make the case to my mother to avoid trips to the grocery store, and to try to modify the situation involving my brother for my parents' protection. Instead, it seems that the tide of the virus is soon to wash over all of us despite our efforts to contain it, and that one can only hope that his or her immune system is neither under- nor over-reactive when faced with fighting it off.
This board is a fantastic source of de facto psychotherapy, and I guess I'm now looking for more. The good news is that....
I'm very sorry to hear that, but I am still uncertain what it is that is making your case "harder" for your mother to avoid trips to the grocery store. The slow progress on a vaccine? The failure to find a game changing treatment? I guess it seems like, if anything, the bad news about the progress of SARS-COV-2 would suggest you have a stronger case for her to stay in, not a weaker one?

Yeah, what's the good news here? Even the worst-hit place in the US isn't all that close to herd immunity (which I've seen as starting at 50-70%, though that could be wrong). If NYC's experience is what it takes to get 1/3 of the way to herd immunity in a short timeframe... eesh, that's not a happy thought.

RE: New York antibody study results - Crafter Artisan - 04-23-2020

(04-23-2020, 05:12 PM)DenverCard Wrote: And motivation by many to do the hard work of social isolation has to be waning, even as one is constantly exposed to ever-present accounts of suffering that are hard to bear.

I was diagnosed with Asperger's syndrome when I was 4 years old. I've been practicing social distancing for 37 years now. :-O