Based on those antibody tests and assuming the death rate is undercounted. We are looking at around 0.8-1% mortality rate which is significantly worse than the flu still, but not nearly as bad as originally thought.

When its all said and done, its probably gonna end up higher than that, could still be ~1%+.

1) This is assumeing that the way they got the survey info is done right, and the randomness of its sample size reflects the rest of society at large in that area.

So its not 100% certain in anyway.
2) 3000 is a decent enough sample size but, theres still error margins that can effect things.

3) Plus death lags, if you test for antibodies "now", you need to factor in the death lag (not look at current deaths).
Dieing to this thing can take a week or two.

Basically 1-2 weeks from now, we should look at deaths in NYC (+add in the home deaths)
and then we should be able to get a more accuate number of deaths this thing causes.

^ my thinking too, at minimum I'd suspect number to be over 0.8%.

Yeah this is like 8-16 times more deadly than a flu (bad ones are usually like 0.1%).
Then you need to factor in how much more easily it spreads (so larger amounts of people could get it).
(flu have R0 like 1.3 (on avg 1 person infects 1,3 others), while coronavirus is supposedly over 3, 1 person infects 3 others)

This could still be like getting 19-37 years of flu all at once (if you let it infect like 70% to reach herd immunity).
(which is why we re now all practising social distanceing)

*OBS!  
That 0.8% is just for the US strain of the virus (which supposedly is abit milder). This also assumes hospitals can keep up with demand, and treatments.
In 3rd world countries, I bet its much higher.

City is ~21%. Its in the same post you quoted. 

~80% of the population in NYC are still vunerable to it.

So yes a 2nd wave could still be way more than it has currently killed in NYC.
Also what right now is 0.8-1% mortality rates, might be higher if you get both coronavirus + normal flu at once.

Normal flu doesnt go away, just because another virus is out there spreading.
Thats why experts suspect a 2nd wave to be much much worse than the first one.
(history also shows this, with the spanish flu)

I found the article which suggest as many as 2.7 million New Yorkers have already had the virus.
It also says the the virus must have been circulating since early Februari.

That's a date range of 82 days, including today.

It's mathematically possible if at least 12 people were already infected Februari 1st, then unhampered growth all the way to today would make it reach 2.7 million people today. However these anti body tests are from people already done and over with the disease, can't have anti bodies until after the incubation time thus substract at least 5 days from when the tests were taken. Say it only took a week to take all those blood samples and get the analyzed, so let's substract 8 days from the 82 (5 incubation and 3 for mid point in testing), 76 days to let it grow.

New Yorkers must really suck at social distancing, or it's more infectious and R0 of 2.2 is incorrect. The math says at least 26 actively infected people must have been walking around in NYC on Februari 1st to make this possible. It's possible, yet either the R0 of 2.2 is wrong and the virus is far more infectious or New Yorkers really suck at social distancing and all the measures did absolutely nothing at all.


https://www.iheartradio.ca/610cktb/news/covid-19-82-yr-old-woman-is-new-york-s-first-coronavirus-death-1.10755441
The [first covid19] victim was an 82-year-old woman who passed away at a New York City hospital after being admitted on March 3rd.

That was reported on March 14th. If it was already spreading since early Februari, then why did it take so long for the first death to appear? Perhaps earlier deaths went undetected like in California.
https://globalnews.ca/news/6856758/coronavirus-california-early-deaths/
Two people with the coronavirus died in California as much as three weeks before the U.S. reported its first death from the disease in late February


Ok lets look at the test method

State researchers sampled blood from the approximately 3,000 people they had tested over two days, including about 1,300 in New York City, at grocery and big-box stores.

3000, decent sample size, however that's not a random sample. That's testing people that still go out to stores. People that are more at risk of exposure vs those staying at home, having done their shopping earlier or get their food delivered. Also chances are you will end up testing those that frequent the stores more often vs those that do a single run to minimize exposure. I also assume it was voluntary, and those that are more careful will naturally avoid participating.


What's the purpose of this test

A while... Not sure I can find that date on my calendar :)


Biased sample, math that doesn't fit very well, suggesting its far more contagious than we thought and all our current measures are for nothing, only raising more questions. It's good to do these tests, but make it a random sample at least ugh.

"New Yorkers must really suck at social distancing, or it's more infectious and R0 of 2.2 is incorrect. "

Havn't they floated numbers around of it being near R0= ~3 ?

*edit:

"3000, decent sample size, however that's not a random sample. That's testing people that still go out to stores. People that are more at risk of exposure vs those staying at home, having done their shopping earlier or get their food delivered. Also chances are you will end up testing those that frequent the stores more often vs those that do a single run to minimize exposure. I also assume it was voluntary, and those that are more careful will naturally avoid participating."

^ this all sounds like good arguements to me.

That survey is likely overestimateing the amount infected % by abit.

While there are quick polling methods and tests for some diseases that can gather results in a few hours, I strongly doubt the results you're seeing pertain to today as opposed to samples gathered over the course of a few days a while back, and then the time needed to confirm results. Besides, these particular antibodies take weeks after the onset of symptoms to produce in measurable quantities that are able to be detected after the onset of symptoms (months or years even, depending on the disease, but likely on the lower range for this one).

Also, NYC, for instance, seems to be doing a fairly complete job of counting all probable deaths, since the total number of Covid-19 deaths (including the probable cases) are more than a match for the excess mortality in the city, versus the average, since the beginning of March. More, even.

True different numbers have been floating around for example here

https://www.forbes.com/sites/tarahaelle/2020/04/07/the-covid19-coronavirus-disease-may-be-twice-as-contagious-as-we-thought/#fa75e4f29a6a
https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article?deliveryName=USCDC_333-DM25287

A single person with COVID-19 may be more likely to infect up to 5 or 6 other people, rather than 2 or 3, suggests a new study of Chinese data from the CDC.

That's if you still want to trust Chinese data at this point :)


It's a double edged sword though:

The new study, published in the Emerging Infectious Diseases journal, shifts the R0 for COVID-19 from about 2.2 to about 5.7. With the lower number, only 55% of a population needs to be immune from COVID-19 to stop its spread through herd immunity. Herd immunity refers to enough of a population being immune to a disease that the disease cannot travel through it. 

But if more people get infected from a single person with COVID-19, then more people need to be protected from the disease to stop it from continuing to spread. With an R0 of 5.7, approximately 82% of the population needs to be immune to reach herd immunity and stop the disease from spreading easily through the population, the researchers concluded.


They're lowering the incubation time as well

The new calculations also estimate the incubation period—the time from being exposed to the virus and developing symptoms—to be an average of 4.2 days, which is in line with most other estimates (though symptoms can still take up to 14 days to show up).


Doubling time of 2.3 to 3.3 days instead of 6 to 7 days.
The growth rate r is estimated to be 0.29/day (95% CI 0.21–0.37/day), corresponding to a doubling time of 2.4 days
Quite a difference.


It all means we need to be extra careful and more diligent with social distancing

We found R₀ is likely to be 5.7 given our current state of knowledge, with a broad 95% CI (3.8–8.9). Among many factors, the lack of awareness of this new pathogen and the Lunar New Year travel and gathering in early and mid-January 2020 might or might not play a role in the high R₀. A recent study based on structural analysis of the virus particles suggests SARS-CoV-2 has a much higher affinity to the receptor needed for cell entry than the 2003 SARS virus (21), providing a molecular basis for the high infectiousness of SARS-CoV-2.

How contagious SARS-CoV-2 is in other countries remains to be seen. Given the rapid rate of spread as seen in current outbreaks in Europe, we need to be aware of the difficulty of controlling SARS-CoV-2 once it establishes sustained human-to-human transmission in a new population (20). Our results suggest that a combination of control measures, including early and active surveillance, quarantine, and especially strong social distancing efforts, are needed to slow down or stop the spread of the virus. If these measures are not implemented early and strongly, the virus has the potential to spread rapidly and infect a large fraction of the population, overwhelming healthcare systems. Fortunately, the decline in newly confirmed cases in China and South Korea in March 2020 and the stably low incidences in Taiwan, Hong Kong, and Singapore strongly suggest that the spread of the virus can be contained with early and appropriate measures.

Even if 20% indeed already have anti bodies in NYC, it won't stop until 82% has been infected, which doesn't mean it won't reach the last 18%. It just means that you need 82% with anti bodies to prevent another wave from taking hold, hoping the anti bodies are and stay strong enough to prevent another outbreak.

Better off waiting until all this garbage is over and done with to study hydroxycloroquine and focus on actually finding drugs that combat the coronavirus.

We only have finite resources, we should be collectively focusing on solving the issue and not focusing on what-ifs like hydroxychloroquine just because the president thinks he is a medical expert and heard it might be effective from a friend whose sisters mother saw a meme on facebook.

There are cases of people overcoming Covid without producing antibodies. T-cells and cytokines can take care of it before antibodies are needed.

The IgG antibody test doesn't become 95%+ accurate until after ~21days - the test gives false negatives until the antibodies are high enough to register.

The 2nd wave of Spanish Flu killed more because it had mutated to become more deadly to the fit/healthy. The people who caught the milder version in the 1st wave had immunity to the deadlier 2nd wave strain.