Looks like you have a possibly important point:

If so, then they would be well on the way to herd immunity and, thus, essentially at the end new cases and the end of the epidemic.

So, for your point, at

https://www.breitbart.com/politics/2020/04/23/andrew-cuomo-1...

is in part:

"Andrew Cuomo: 13.9% of New Yorkers Tested Positive for Coronavirus Antibodies; 21% in NYC"

The 21% is huge.

So, it looks like the virus spread much faster than symptoms indicated and now ballpark 1/4th NYC has been "exposed" to the virus and is either infected without symptoms or recovered without ever having significant or any symptoms. Amazing. So, if want to accept the usual situation for viruses, then the 1/4 of the population soon can't get or transmit the virus.

Ah, but wait; there's more: As at

https://www.msn.com/en-us/news/us/in-four-us-state-prisons-n...

is, call it an exploitation of a captive audience,

> When the first cases of the new coronavirus surfaced in Ohio’s prisons, the director in charge felt like she was fighting a ghost.

> “We weren’t always able to pinpoint where all the cases were coming from,” said Annette Chambers-Smith, director of the Ohio Department of Rehabilitation and Correction. As the virus spread, they began mass testing.

> They started with the Marion Correctional Institution, which houses 2,500 prisoners in north central Ohio, many of them older with pre-existing health conditions. After testing 2,300 inmates for the coronavirus, they were shocked. Of the 2,028 who tested positive, close to 95% had no symptoms.

> “It was very surprising,” said Chambers-Smith, who oversees the state’s 28 correctional facilities.

and the article has more such data.

Then if want to accept an estimate that 50% of the population immune means herd immunity, NYC is ballpark half way to herd immunity which would be close to the end of the epidemic. E.g., even people in NYC so far never exposed to the virus would not get infected even from infected new arrivals before they were recovered or dead.

So, a guess is that the virus SARS-COV-2 is very strange in two respects: (1) It is astoundingly communicative, that is, spreads very easily and (2) has some huge fraction of people with the virus but without symptoms.

A guess at an explanation: In NYC, the virus was often getting spread just via the air, e.g., via building central HVAC systems?

The good news, if want to believe all such evidence and related common assumptions, is that we can get to a fraction of the population with immunity large enough to have herd immunity and, thus, essentially be well on the way to the end of the epidemic, all surprisingly quickly.

Only, there's no evidence that folks who recover from COVID are immune. Herd immunity might never come, so lockdowns remain beneficial in reducing hospital crowding.

https://www.npr.org/sections/coronavirus-live-updates/2020/0...

Yup. But the usual assumption, experience, history, situation, whatever of viruses is that recovery means immunity at least for some significant time, say, a year or so.

Also, I stated

> So, if want to accept the usual situation for viruses,

I didn't explicitly repeat this qualification just before your quote but went for fewer words.

Here in the SF Bay Area, I'm seeing a 40% decay weekly in hospital admissions. If you assume infections outnumber hospital admissions by 20x, it's going to be months before we reach the low case counts (1 per million) needed for contact tracing and suppression efforts amid semi-normal activities. And that's assuming we keep the 40% decay rate, and don't encounter subpopulations with higher Rt's that keep the virus circulating much longer or even growing.

>> So, if want to accept the usual situation for viruses...

You're saying that we should assume "normal situation" in the face of evidence that your assumptions do not hold. Anything you say based on this faulty assumption is hardly worth consideration.

Folks don't develop immunity to this virus. They can get re-infected immediately after recovering. Herd immunity is a phenomenon observed elsewhere, but not here.

This is an extraordinary claim without evidence.

There's a few case reports of "reinfection", but they are rare. In all cases A) symptoms were mild, and B) researchers were unable to culture SARS-CoV-2 from them. Many viral illnesses have people shed virus again a few times after "recovering", and this seems no different.

A bigger concern is, humans seem to lose antibodies to coronaviruses with time-- this is how we get the common cold again and again. But infections after the first time seem to be less severe, thanks to longer-lived immunity from memory t-cells, etc. And at least for SARS-COV-1, immunity lasted quite a bit longer than typical for other human coronaviruses, with decent antibody titers at 3 years (no followup past then).

Not really! As you say, this virus is new. Soooooo, we are short on info. So, we should entertain several possibilities.

I didn't say "should" and, to entertain more than one possibility, only said "If"! Biggie difference.

Yup, we don't know. If we do a lot of very well designed and executed statistical trials, controlled, double blind, randomized, simple random sample, stratified sample, etc., then maybe in five years we will know enough to be sure on all the major points, across seasons, ages, other medical conditions, reinfection, spreading via HVAC systems, therapeutics with dosages, side effects, and contraindications, vaccines with number of shots, contraindications, etc. Ah, just wait five years!!!!

Well, nope, to paraphrase, we go to war with the info we have and not the info we want.

So, for the info we have, from the history of viruses, once recovered, then likely immune for a long time; for now we have to take that seriously and maybe are in effect forced to act as if we believe it.

Yup, there are reports of "reinfection" from maybe China or South Korea -- I didn't pay much attention to those reports due to concerns about, call it, data quality. But, net, yup, maybe in some cases, maybe even in all cases, recovery does not mean immunity.

At high cost, we will be finding out with some relatively good data, and in less than five years! Did I mention high cost?