One in Three Americans Already Had Covid-19 by the End of 2020 | Hacker News Reader

One in Three Americans Already Had Covid-19 by the End of 2020

publichealth.columbia.edu

49 pointsaazaa22 comments

"The study is the first to comprehensively quantify the overall burden and characteristics of COVID-19 in the U.S. during 2020..."

Well, it's not been widely reported, but if you dig through the cdc.gov website you can find their estimate of the multiple (actual cases / PCR-confirmed cases), which has been between 4 and 5 (closer to 4) for a while now (higher in early 2020). It doesn't get the press it should, but it's not a new finding.

https://covid.cdc.gov/covid-data-tracker/#serology-surveilla...

At about that time there were 400k deaths, which implies an infection fatality rate of 0.4%. This is consistent with various studies I ran across that point to a 0.2%, 0.3% fatality rate.

There is strong evidence that infections have been massively under-detected since the beginning of the pandemic, by a factor of 5x to 100x [1][2]. Recent estimates put the global average IFR closer to 0.15% [3], which is likely still over-estimated, and will likely continue to decrease as more data is collected.

[1] Evaluating the massive underreporting and undertesting of COVID-19 cases in multiple global epicenters https://www.sciencedirect.com/science/article/pii/S253104372...

[2] Undiagnosed SARS-CoV-2 seropositivity during the first 6 months of the COVID-19 pandemic in the United States https://stm.sciencemag.org/content/13/601/eabh3826

[3] Reconciling estimates of global spread and infection fatality rates of COVID- 19: An overview of systematic evaluations https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/eci.13...

This is what I also believe. However it is really hard to count reliably. Maybe one day we will know for sure.

~1% with good care was closer last time I checked. There was a good paper explaining differences between locations were mostly because of demographics and the total result was in that range. 0.4% is the rate of total NYC residents who have already died for example. So for that to be the IFR NYC would have had to have 100% infection of its population. Not impossible but seems unlikely.

Without good care, like when hospitals get overwhelmed by a wave, 3%+ was likely. But that heavily depends on the exact pressure and maybe we've gotten better at treating it anyway.

The IFR is not the same for every demographic. In a population which is obese and older it will be higher.

More than half of adults in New York are overweight or obese (https://www1.nyc.gov/site/doh/health/health-topics/obesity.p...)

If you are obese and contract the virus you are 113% more likely to need hospitalisation and 48% more likely to die than normal weight or overweight people.

https://jamanetwork.com/journals/jama/fullarticle/2772071

> So for that to be the IFR NYC would have had to have 100% infection of its population. Not impossible but seems unlikely.

If NYC had 100% infection by the end of 2020, post-infection immunity is a lot worse than every study of that topic has suggested.

Important to distinguish between the infection fatality rate, and the hospitalization fatality rate. People who never know they're infected, or know they're sick but don't bother getting a PCR test because they're just going to stay home and isolate regardless, don't show up in the hospitalization fatality rate.

So about twice as bad as the flu? https://www.cdc.gov/flu/about/burden/2017-2018.htm

Why not compare apples and apples? That is, because of covid, people were wearing masks, distancing, large crowds were outlawed, etc. So comparing covid stats of 2020 to flu stats of 2017-18 isn't too useful. Why not compare flu stats to covid stats in the same time window? Because of those massive, intrusive efforts to stop the spread of covid, flu numbers were/are way down. The number of flu deaths in the US in 2020 was something like ~700 (usually it is 30,000), and covid was ~400,000 deaths.

So, no, not 2x worse.

Maybe. However if I understand correctly it is much more contagious than the flu which means that this 0.4% will die almost at the same time (say in a year), while the flu will have to circulate for years until it claims its own 0.1% (or whatever percent). I am not an expert, btw.

Why isn’t a natural infection treated as equivalent to a vaccine? The CDC’s own slide deck for Delta (https://www.documentcloud.org/documents/21026654-57c98604-3b...) acknowledges that a natural immunity of 35% would push R0 for Delta below 1 even with no masking at present vaccination rates.

If the numbers quote above are correct, then the majority of the “unvaccinated” have already been exposed to COVID. And yet, they are dying by the hundreds of thousands and running out of ICU beds to die in.

So, I think we already know how that works. Or doesn’t work, as the current example shows so clearly.

As of today, Covid has killed 0.06% of the world’s population. Perhaps we are over-reacting?

Maybe it’s only 0.06% because we are over-reacting. And it’s not over.

The global numbers may be somewhat skewed by China miraculously reporting almost no new COVID cases since March 2020.

I think it would be short-sighted to deny the efficacy of their strategy of welding people inside their homes.

We (humans) overreact to new things. We are overreacting slightly less as time goes by. It is much like the post-9/11 overreaction to terrorism. It takes time for it so subside. The post-9/11 overreaction took about a decade; we seem to be self-correcting much faster in this case. But, yeah, still overreacting at this point.

And for how long COVID antibodies will last? In the case of Spanish flu they lasted 100 years.[0]

[0] https://www.nationalgeographic.com/science/article/flu-survi...

So I am still curious about what is going to happen to countries who have employed so far the "zero-covid" strategy once they finally open up.

Granted, I assume most of their population will be vaccinated, but there seems to be growing evidence that natural immunity gives you at least equal, or in some cases better protection than an mRNA jab(specially against new variants).

It also seems to be an established fact that older folks, who happen to be the most vulnerable group, do not respond as well to vaccines as one would've hoped.

I suspect that countries like Australia, NZ and China will still have to endure reasonably big COVID waves - surely they will be attenuated by the high vax rate, but will still be deadly enough to stress their healthcare system.

I do believe that they had the winning strategy against covid, but there are still unkwnown unknowns.

Surveillance data in Canada collected Nov 2020 thru March 2021 had roughly 1 to 4% of Canadians having antibodies from previous infections, depending on province.

We're now losing control with the most infectious variants. But most of us seem to still haven't had it, including most unvaccinated (about 15% of adults). Accepting we're probably all going to be exposed eventually is a bit annoying after all this, but the fully vaccinated don't have too much to worry about. The main worry remains burden on the healthcare system for treating the unvaccinated. There are only so many ICU beds -- less than half as many per capita in the USA -- and now that some regions are running out of those even the fully vaccinated are in trouble if they need other urgent medical care. The plan, if we can call it that, is to keep the rate low enough until everyone has had it that hospitalisations are manageable.

One thing I've noticed is that some Americans don't appreciate how politically unacceptable it is for much of the public to get COVID-19 in countries that have had some success in containment. New Zealand appears ready to become a hermit kingdom forever if that's what it will take. Anecdotally, my mother has been fully vaccinated and looks at me like a dog with two heads when I try to explain that she's at comparable risk of serious illness to influenza when fully vaccinated. It's the plague and a "managed" exposure is unthinkable. Do not underestimate the political will there to maintain countermeasures, whether it makes sense or not.

If you look at Australia right now, their infection rates are rising at a rapid clip. So they may have a lot more people infected soon, and the difference between them and Europe and N. America may not be that great.

China probably had a lot more people infected than we (or they) know, because they were first, and there was no testing capacity at the time. Even if they were honestly forthcoming with everything they knew about, they probably had way more infections than they knew, because of going first.

Now, in the case of New Zealand, you may be correct, they might be in for a hard time. Having almost nobody infected before, and then finally getting the latest, fastest-spreading variant when they do get it, might be a bad thing. But, hopefully, this is countered by the fact that people who are vaccinated first have much milder symptoms.

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