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Comment by walterbell | Hacker News Reader

> Importantly, we detected SARS-CoV-2−reactive CD4+ T cells in ~40-60% of unexposed individuals, suggesting cross-reactive T cell recognition between circulating ‘common cold’ coronaviruses and SARS-Cov-2

This is saying that 40-60% of existing immune responses (learned over many years of previous coronaviruses) are also protective against the SARS-Cov-2 virus which causes Covid-19 disease.

There is a time-based arms race between virus replication & immune defense. If these subjects are otherwise healthy, their immune system should have a good chance of clearing the Covid-19 virus successfully, because it has a "running start" against the new virus.

After recovery, their adaptive immune system should have developed an additional immune response that is customized to defend against Covid-19.

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> This is saying that 40-60% of existing immune responses (learned over many years of previous coronaviruses) are also protective against the SARS-Cov-2 virus which causes Covid-19 disease.

Existing cross-reactive adaptive immune cells or antibody != protection from this new virus. It only shows that these viruses are similar so there is some cross-reactivity from immune cells and antibodies designed to detect some viral epitopes (not terribly surprising). The question of whether these CD4+ t-cells that cross react are protective in humans would still need to be determined. (ie, what you’re saying is possible but not at all a foregone conclusion).

The possibility of ADE mentioned in the discussion, for example, would actually mean that some cross-reactivity (in this case of antibody) could actually cause very severe disease in those individuals. This, by the way, would also be a good explanation for why more naive individuals to all human coronaviruses (ie children) do not generally get as severe of disease.

Yes, as one of the authors said on Twitter, this doesn't prove anything about the effects on SARS-CoV-2 immunity, but it is suggestive:

"Whether this immunity is relevant in influencing clinical outcomes is unknown, but it is tempting to speculate that the crossreactive CD4+ T cells may be of value in protective immunity, based on SARS and flu data."

https://twitter.com/profshanecrotty/status/12610523537733632...

>After recovery, their adaptive immune system should have developed an additional immune response that is customized to defend against Covid-19.

The extent antibody-dependent enhancement causes mortality is questionable. Ongoing studies (https://clinicaltrials.gov/ct2/show/NCT04324021) to treat cytokine storm cases will hopefully be able to better estimate it.

What if we infected people purposefully with common cold coronaviruses to help them get a level of immunity? Common cold isn't fatal or dangerous right? Could this work as a 'vaccine' or prophylactic? You wouldn't even need to test people with this test before doing that because the people with immunity will just not get sick with the cold.

It’s not the “common cold” as in rhinovirus, about 10-30% of cases of cold are caused by corona viruses other than SARS-COV2.

Since corona viruses are quite common it will be hard to know which one causes this immune response.

The interesting part is that early on tests of MERS and SARS survivors didn’t indicate an adaptive immune response against COVID-19.

From what I've read, immunity to other coronaviruses typically only lasts a year or so. SARS hasn't infected anyone in over a decade, and it's been a few years since a MERS outbreak.

Everyone already gets exposed to common colds, hence common.

> If they are otherwise healthy, their immune system should have a good chance of clearing the Covid-19 virus

Yet we decimated our economy out of an absolute panic and still continue to push for lockdown even when numbers show it’s time to start things again.

> decimated our economy out of an absolute panic and still continue to push for lockdown

80,000 Americans died, and thousands more will die before this is over.

And that's with the lockdowns. The figures could easily be an order of magnitude or more worse be now without them. We successfully managed to not exceed the capacity of our healthcare system, for the most part.

There is still a piper to pay for the lockdowns, and that is the patients who will die due to untreated heart disease, missed cancer treatments and surgeries, mental health problems, und so weiter. Not to mention all the people who will now find their disease at a later date and suffer a worse prognosis for it. The lockdowns could have created more deaths and suffering than were prevented, but we won't know for some time.

Social distancing was always going to happen. Restaurants here in NYC were running at one quarter their normal business in the days leading up to the official lockdown. People aren't stupid, and will choose to stay home when a pandemic is ravaging their community regardless of what official guidance might be.

There's no world in which the pandemic is running unchecked through society and people are acting like everything is fine and normal and doing all the usual stuff they're accustomed to.

This is a conflation of what the virus itself has down, and the response to it.

Not at all. Hospitals shut down elective procedures, not because they were running out of room, but because they were ordered to do so. That freed capacity may have been necessary in NYC, and maybe not, but nowhere else was it necessary.

That's not past tense yet...

Many many people will lose their homes, insurance, and die from other illnesses as a result of shutting down

Loss of a home or an insurance can be temporary.

The loss of a loved one is never temporary.

At the expense of all other medical procedures that people needed, let us not forget. We did all of this despite a whole bunch of people effectively having already been vaccinated against COVID-19.

> effectively having already been vaccinated against COVID-19

There is no vaccine against COVID-19... unless you consider drinking bleach or dying...

"Effectively" is the meaning I got from this article.

The paper doesn't say that at all. It isn't known whether these antibodies are effective at fighting SARS-CoV-2 or how effective they are.

The actual deaths we've seen and the overwhelming of hospitals in multiple countries refute the kind of narrative you're fantasizing about.

No, they're saying that 40 to 60% of people have antibodies that can make it easier to fight Covid-19... this could be one of the reasons the elderly die more often for example.

The reason the elderly died more often is because they didn't quarantine retirement homes, and instead send infected individuals into them.

It's more like 90K now.

However, for perspective, North America (which is mainly the US) has had 1.65M cases and 100K deaths, while Europe has had 1.76M cases and 161K deaths.

With all the focus on the US as the single country with by far the most cases, it seems to have not registered with most people that Europe as a whole is of comparable size, has had a comparable number of cases, and has seen a lot more casualties.

I wouldn't draw the conclusion that this validates the US health care system, or the decisions of authorities, because of other variables, but it makes me wonder if a narrative about how terrible the US is has been allowed to obscure the facts.

Europe as a whole has more than twice the population of US.

Which is why I gave numbers for North America.

The stats I was looking at appear to be based on a definition of Europe that is about 700 million, while "North America" is about 590 million.

> even when numbers show it’s time to start things again.

Which numbers would those be? Because I'm looking at https://coronavirus.jhu.edu/data/new-cases, and it does not in any way support your claim.

It seems lazy for that website to not show per-capita numbers or positive test percentage numbers.

https://coronavirus.1point3acres.com/en/test

Positive test percentage numbers depend greatly on the rate of testing. People with the most severe symptoms are generally tested first.

A declining number of hospital beds used is an extremely good sign, but there is very limited data for this nationwide.

For most of the United States the total lockdown has been overkill. A better way to compare the US to most European countries would be to compare individual states and even then some states have rural populations that would have been fine without lockdowns. For example, New York City is one of the hardest hit cities but the rest of the state of New York has had significantly less cases and deaths. Is this because of the lockdowns? Probably, but at the same time our hospitals have not been running at capacity or even close to that (some have even furloughed workers because all elective procedures have been cancelled).

If the goal is to find a cure before we lift lockdowns we better do something to help those economically impacted by them (and giving away free money is not a viable option). If the goal is to not overwhelm our healthcare systems we are doing that great but a country wide lockdown is not viable either. The New York Times has a good map [0] to show how little most of the country has been affected. That is why state governments should be handling the outbreaks in their own state instead of shutting down the country all together.

These lockdowns were implemented because we had no idea how this virus worked or where it was. We have a much better idea now and each state can act accordingly.

[0]: https://www.nytimes.com/interactive/2020/us/coronavirus-us-c...

Georgia is a good example of a state that has started to open it's economy and is still seeing a decline in new cases. NPR has been tracking state restrictions and Georgia lifted some restrictions April 24[0] more restrictions were lifted May 1

[0]: https://www.npr.org/847415273#georgia

edit: April 24 was earlier than May 1 for some lifted restrictions.

It appears that GA is also engaging in some reporting shenanigans to make things look better than they are:

https://twitter.com/GAFollowers/status/1261688916375212037?s...

Bad reporting or not the new cases are declining.

Georgia's cities and counties mostly put their own measures in place without waiting for the governor to decide to do something. I don't think they're waiting for or depending on the state's call on it.

Even better. Atlanta, GA is very different from Savannah, GA and both can act in a way that is best for each city.

Maybe, just maybe you shouldn't look at new cases as your measurement when you are constantly ramping up testing. If you test more people of course you will find more people with the virus. You should be looking at hospitalizations and those numbers are pretty much down across the board.

An alternative way to look at this is that you shouldn't remotely consider reopening if you don't even have enough testing capacity available to identify nearly every case. You can't control outbreaks if you don't have the data needed for contact tracing.

Testing is a point-in-time measurement. Means little if someone with a negative test can get infected an hour later.

We should instead be teaching people to recognize early symptoms so they can immediately isolate during the time-bounded phase of virus shedding.

Testing is sanitation theater with the side effect of creating a surveillance society.

It's pretty clear that a positive test is the early symptom for a large percentage of people.

It's also not the interval immediately after infection takes place (your hour later) that matters, it's the period starting a few days later. Get them out of circulation before they have a chance to spread the virus and we can slow it down further than we have till now, even with more activity taking place.

Why is that? I don't see the need for testing when we already know that folks under 60 are usually fine if they take the standard precautions, and everyone over 60 or in a risk group should remain isolated.

The testing is nice to have, but shouldn't really alter people's behavior.

If you look at % positive it accounts for increases in testing ability. So are you just testing more, or are you actually finding an increase in cases in your sample of the total population. That is what they're looking at to get a true determination of if the infection rate is increasing, decreasing or flat.

There's plenty of evidence that people not wanting to get sick is a big factor in the economic slowdown, it's not just a top down policy choice.

Well to a large extent that’s policy driven as well. The media have been pounding the message safer at home unrelentingly for weeks. Make no mistake, the virus is real, it is far more deadly than the flu, and while there’s no natural experiment it’s likely the lockdown saved lives.

That being said, the messaging hasn’t been calibrated very well.

Everyone talks about the post 9/11 “security theater” of the TSA, but because we’re unable to reasonably assess the threat, today we’ve got equivalent public health theater, but the TSA is us.

Classic conflation of the effects of a pandemic itself with the measures taken to fight it. Things would not be going along swimmingly if governments hadn't stepped in with social distancing measures; instead there'd be a lot more dead and everyone wouldn't be leaving their home anyway out of raw fear.

Sweden begs to differ with this statement as the as the misleading headline article from the NY times shows that their numbers aren't meaningfully different than other European countries which did lockdown. UK which has a lockdown policy was quite a bit higher.

CDC own numbers on this aren't really supporting the panic level either.

https://www.cdc.gov/nchs/nvss/vsrr/covid19/index.htm

Pneumonia is still stomping covid19 as far as deaths. Death projections are made from the 2017-2019 data and as of now they're at 101% of their protections. That number moves up and down but has been sticking really close to 100%. With 60+k unexpected covid19 we should be around 105-107% deaths but we're not.

Things aren't over yet but all the be data coming out is very much supporting that is has been a massive overreaction. If we're going to overreact for the purpose of saving lives, why don't we don't we do it to solve the 9.1 million deaths from hunger and hunger related issues?

> UK which has a lockdown policy was quite a bit higher.

No, the UK was following in Sweden's footsteps until forecasts became untenable, by which time a lot of damage had been already done: https://www.technologyreview.com/2020/03/16/905285/uk-droppi...

Compared to its neighbours, Sweden is doing remarkably bad: https://twitter.com/MarkkuPeltonen/status/126113845423635251...

In terms of economy, Sweden's GDP is expected to fall about as much as rest of the EU (~7%).

https://www.nytimes.com/interactive/2020/05/15/world/europe/...

UK was just one example. Sweden is no worse off that other European countries. You can cherry pick the neighbors but that's doing a disservice.

Of course their GDP is expected to fall. All of the countries are tightly linked together in their economic outcomes.

Sweden and Norway were "tied" a little while ago. Not so much, now.

Sweden is a lot more locked down than you seem to think it is, and they are experiencing the same bad economic effects: https://www.ft.com/content/93105160-dcb4-4721-9e58-a7b262cd4...

The main difference is that they have a lot more deaths relative to many other countries that handled social distancing better.

I have a question on this regard, since my digging didn't find anything. Is there any correlation between where the first clusters of cases where found (schools, hospitals, offices, houses...) and the subsequent hit on the health system?

> Yet we decimated our economy out of an absolute panic and still continue to push for lockdown even when numbers show it’s time to start things again.

Remember: the correct recation to a situation like this will probably look like an extreme overreaction.

There is basically no way of telling the adequate response from a complete overreaction right now.

Even if it turns out that in the end the IFR of the disease was just 0.1%, or that 50% had existing immunity... then that will only change after the fact what would have been the correct response. The decision needs to be made without that information.

Yes, look at Greece, they implemented extreme measures. As a result, they basically had no issues at all with the virus compared to neighbouring Italy and Turkey.

And look at Japan, where they half-assed their response and turned out better (fewer deaths per capita) than Greece. I think most commentary assigns way too much credit/blame to the government's response, while ignoring yet-unknown environmental, pre-existing cultural/behavioral, genetic, or other factors. I'm saying this not to excuse government incompetence, but to counter the persistent suggestion that everyone could have the same good result as e.g. South Korea if only their government had responded in the same way.

if we had not locked down everywhere would have been like italy or nyc or worse. remember that deaths peaked at 2500 per day in the usa with a lockdown. thats 5x of a bad flu season with no lockdown.

NYC and surroundings are very different than FL are very different than California. I agree NYC was a complete disaster, but it doesn't follow that Dallas would have met the same fate.

Yes, and NYC locked down... imagine if NYC hadn't...

I'm in NYC and our biggest problem here is that our dumbass mayor and governor waited at least a week too late to shut everything down. If we'd locked down sooner we'd have had a lot fewer deaths and would be much further along the road of reopening already. One week on the front end is worth many weeks on the back end when you're talking exponential growth.

What do you think would happen to the economy if we let the virus run free through the population, and eventually everyone would be too scared to leave their house and quit showing up to their job?

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