What other coronaviruses tell us about SARS-CoV-2

Yes.

Being around a positive person continually for several days at home would mean a lot more exposure than many people would get when encountering others in public.

Maybe? No one knows for sure. We can't directly measure the dose of virions each person receives. There is a huge variations in contagiousness between patients based on factors that are still unclear. Proper use of PPE by caregivers can also have a huge impact.

Yes. Separate as much as possible, don't share a bathroom at all.

Does it not logically follow that if the dose can be precisely controlled, it could help your body start developing antibodies sooner?

I suspect this would be facted on operators (trains, bus, etc.) versus support/construction/maintenance staff.

Yes, but they're workers. People generally retire at 65, and in the MTA, I believe you can get a full pension at 55. The population that pushes up the mortality numbers are 70+, and they're not driving a bus or a train anymore.

Age is relevant here. I don't recall the numbers, but I read that a disproportionate amount of younger people who have died from covid-19 or had sever cases, were healthcare workers. And the theory was that viral load plays a part.

The Chinese doctor who blew the whistle on covid-19 died from it, and I believe he was an otherwise healthy 30-something.

for SARS-Cov (the first one from 2003) there is some data and it's not pretty :/

There is data showing that flu vaccination reduces the chance of heart attack. The effect is about as strong as giving up smoking.

This was also confirmed by a physician from Innsbruck, Austria that looked after healthy young adults that were divers and got the virus - all of them had only mild symptoms but most lost the fitness to dive anymore and lack lung function.

https://www.sportschau.de/weitere/allgemein/corona-lungen-sc... (I did not found an english link)

Yep. Lung damage rarely heals, which has life-long consequences. IIRC, a BBC report mentioned a 30% average decrease in lung function in survivors. Heart, liver, kidneys and possibly other organs are also affected.

I'm not equating Covid-19 to the flu, but ground glass opacities are common among people with influenza. They're also not uncommon in older folks with no history of smoking etc. Right now the evidence of long term or permanent damage to lungs is very muddled and often anecdotal.

Source? It depends on the intervention, but my understanding is that that is not required to be true on the 18mo timeline. I.e. I think the original Imperial College study was calling for for suppression, rather than just avoiding overwhelmed hospitals

I don't think this is a foregone conclusion by any means. Many countries have gotten growth rates low enough that even after 2 years, their whole population won't have gotten it. Some countries might opt to infect everyone (as the US seems to be doing, due largely to chaos and incompetence), but I don't think it's the only option.

A vaccine isn't the be-all-end-all. We can still potentially hold out until there's an effective treatment. Famotidine? Remdesivir? Anything that would reduce the severity of the infection would lead to a better outcome than you're facing currently.

There are a lot of useful interventions that we're figuring out that will help even before we get a vaccine. Lots of antivirals are being studied and those that work will probably be best given in the first few days after symptoms show up, which requires more testing. Figuring out when to give steroids or IL-6 inhibitors after the first week when the virus starts to fade but the danger of cytokine storms gets worse. Figuring out when to flip people onto their stomachs (proning) and how low blood oxygen levels can get before intubation is actually necessary.

If we can keep this thing suppressed for another month summer might provide us with a bit of breathing room to figure out what works and stockpile supplies. But even if not I'd rather get this thing with the medical state of the art a month from now.

I mean, working genes for all the various parts of the virus. Of course it is hijacking the cell's machinery.

Double the official NY COVID deaths figure because excess deaths at home weren't counted.

It's such a breath of fresh air coming on HN where most people are numerate and capable of understanding data.

I actually agree that most parts of the US should carefully open up - the lockdowns have a significant portion of the population in dire straights. Our society can't survive a long-term lockdown intact, I'm convinced.

But that doesn't mean the virus isn't extremely dangerous. It's far worse than the flu. It's irresponsible for folks on social media to insinuate that it's "not even has bad as the flu" based on a few memes they've read.

We have to take great care, or more areas will end up like the Tri-state area. As the GP pointed out, the viral load is extremely important in determining mortality among the younger ages. If there is tons of the virus everywhere, the < 60 mortality rate will increase, possibly dramatically.

Glad to be on HN where most people understand things like CFR vs IFR (as opposed to a vague "death rate" most of social media talks about) along with issues of bias, etc that can affect any of these studies.

> And for that matter, flu kills a ton of people every year, are we going to add another flu to the world without fighting back

I feel like they're realistic limits. People are not gears and you cannot turn humanity off like batteries. There is unrest in Ecuador when cities began running out of morgue space. There's unrest in parts of the world where people haven't seen paychecks for two months. Most high income countries have been overproducing food for years, but we're still losing a lot of food quickly. We're depending on that overproduction slack to hold.

Combined with the difficultly of creating coronavirus vaccines. I've read people attribute the lack of a good SARS1 vaccine due to the economics/capitalism, but there seems there more to it. Animal and human trials have produced vaccines that may not provide long lasting immunity and have dangerous side-effects:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3335060/

A vaccine in less that 5 years feels very unrealistic, not for a safe one. I have a feeling humanity may need to come to the realization that our life expectancy may have been significantly lowered for the next several years, if not decades.

The IHME model has been really interesting for Sweden. While Sweden is saying they have it under control the growth rate of their expected deaths is rising faster than any country. It was projected at about 10k by Aug 4 just a couple of weeks ago, but it is now over 17k expected to die in Sweden. Although they seem to be more OK as a country if their senior citizens die.

I don't think a room would have 10 people with mild cases.

So this needs to be modelled realistically.

I think there's a small chance one person in the room has it for R0 = 2.5 compared with a not quite as small chance one person in the room has it for a lesser R.

Also I also don't think being in a room with multiple people effects load.

I think it's distance. A cough from a person within 50cm is far far worse than 2 people breathing.

So this is my junk science claim, this needs to be backed with numbers. It's not logical R effects load exposure to me, where is this evidence from?

Else this is dangerous information, exactly the same as saying it's just the flu.

I agree. I certainly won't be sending mine back in a rush, not until I am confident they have a manner of control rather than just "well the health services won't be overwhelmed by the dying"

And if you don't break it, then eventually Websters will add it to the dictionary and you'll have been right the whole time.

I can see where that impression came from since it is a generic sounding name, but SARS is not a generic symptom name like "fever" or "cough." There is only the SARS disease, caused by the SARS-cov virus, and the related COVID disease, caused by another strain of the SARS-cov virus. the strain of virus causing covid is of the same species as the virus that caused SARS. In general, biology names are just really annoying and nonsensical, so I totally see where it's easy to be led astray by these annoying, generic sounding names, the reuse of the word SARS for a specific disease and a species of coronavirus strains, all of which are the same single species and are related and are called SARS-cov viruses, but where only one of them causes the disease called SARS, while another one causes the disease called COVID-19. And to add to the confusion, people just refer to COVID-19 as COVID, but all COVID stands for is "Coronavirus Disease." So the coronaviruses are a family of genetically/evolutionarily related viruses, but only one of them, a strain of the sars virus species, causes coronavirus disease. And while lots of diseases cause respiratory issues in the middle east, only one specific coronavirus gets to cause Middle East Respiratory Syndrome

"Taxonomically, SARS-CoV-2 is a strain of severe acute respiratory syndrome-related coronavirus"

https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr...

The official paper announcing the name of SARS-COV-2, Titled: The species Severe acute respiratory syndrome-related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7095448/

I've linked at the bottom a great video from minute earth with some food for thought on this that I recommend watching, I found it really helpful/interesting.

R0 is not necessarily inherent to the virus (although I think australia might use a more restrictive definition that makes it more inherint to the virus), it's based on our behavior to a large extent. MinuteEarth has a great video (i'll link it below) that discusses how Cholera, for example, stayed very severe and yet had a high R0 because it spread through sewage and the sanitation system was not so great, so it didn't matter whether people stayed home since their fecal matter ended up in drinking water anyway. But after sanitation systems improved, cholera's R0 dropped and the less severe mutation meaning higher r0 thing kicked in since you needed more human interaction to get it to spread again.

So with coronavirus, if it mutates to become more severe, maybe it'll mutate back to a SARS like form where it's super lethal which also means it doesn't spread really far. Both SARS and ebola are on that end of the spectrum. But let's say people get overconfident and think they've beat it and don't stay home in the earlier days of the infection when they're not bedridden yet, you could still get a lot of spread. Or, let's say it becomes more severe, but also gains the ability to survive on surfaces for weeks and become airborne when dislodged. Now, your santation procedure for your instacart delivery is no longer enough and the virus could keep spreading through a lockdown. And then there are diseases like HIV, which are ultimately incredibly severe, but have a latency period that allows for infection to keep occuring even with a mechanism of transmission that is a lot more effortful than accidentally coughing near someone. As you mentioned, the asymptomatic spread aspect has echos of htis, where even though the mutation could be severe, it might not have the chilling effect on transmission you'd expect because of asymptomatic and presymptomatic spreaders.

So long story short, I don't know how likely it is that a more lethal mutation appears, but I do think you're right in intuiting that it is possible. Perhaps there are ways to estimate a probability by running simulations on the genome of the most common types of mutations to see what sort of effects we can anticipate. SARS-COV-2 is very closely related to SARS-COV after all, it's just a slightly different straing, even though the SARS outbreak and the COVID outbreaks look so different. I don't think it's impossible that COVID could mutate to have SARS' severity while maintaining COVID's presymptomatic shedding and asymptomatic spread. Maybe as we learn more about it we'll discover that both come from the same mutation and it's a fundamental tradeoff, but I think it's possible that that's not the case.

A disease's guide to world domination from minuteearth: https://www.youtube.com/watch?v=Ch4d9qEKmHE

But isn't that the point? They accepted more deaths up front, but over the long-run those countries should average out about the same per capita, while Sweden avoided immediate negative social/economic impacts.

As stated by others, they are further along in the pandemic in terms of number of people infected. They also have rather large long term care homes and more than half their deaths are in those.

We won't know if that is a winning strategy until a year from now but there is a strong appeal in having not locked everything down. They will be resuming football games with fans and everything at their large stadiums come June.

The death rate is clearly not growing exponentially. Try switching the scale to logarithmic in your link. It's basically linear right now based on some other graphs I've seen, but it's hard to tell due to reporting delays. Since the number of people in hospital has been stable for about two weeks now, I would be very surprised to see the daily deaths increase by a lot.

Is Netherlands comparable with Sweden and Denmark? If not, why not?

Because lockdowns aren’t sustainable, it’s unfair to compare Sweden’s short-term death rate to countries in full lockdown. Let’s see what happens once the lockdowns are lifted and the next wave of infection takes off.

I think there is this and there is that.

First there is definitely propaganda from Sweden or from its sympathizers who see the failure in this crisis as being an example of being wrong in other issues like immigration.

Secondly there are people who try to use Sweden as an example to advance their local economical or political goals.

Third there are people who see this nonsense though and do not want to be in the chain of stupidity.

I'm sure it depends a lot on your location and peer group. In San Francisco, where I live, it's very common for healthy 20- and 30-somethings to get the flu shot every year. I try to remember to get it every year, and there's always friends or coworkers reminding everyone about it every year.

Lots of people, I think. My extended family group chat always has a "did you get your flu shots?" thread around October of every year. Last year when I took my family for the shots, there was a line of probably 100 people on a weekday afternoon.

Most of the people I know at least? It probably varies a lot by location, subcultures and socio-economic groups.

It depends on the country https://en.wikipedia.org/wiki/Influenza_vaccine#Recommendati...

Oversimplifying, it is recommended for people with more than 65(50) years, people with chronic diseases or HIV, and pregnant women and babies from 6 month to 5(2) years. Also people that work or live with them. But each country has it's own rules and recommendations.

I read about the 2017 and 2018 US vaccination rates on the CDC website recently, those years we got an estimated low 40% range vaccination on adults and in the 60% range for children vaccinated.

Well, anyone who has regular visits to a doctor at all, or has prescriptions filled regularly at a pharmacies, will probably pestered about getting flu shots yearly, at least.

If you are young and healthy, I don't think they are pestering you for your sake, but to build immunity and prevent its spread. Healthy people should really look at flu shots as a kind of duty to their fellow citizens, who may be more vulnerable.

Every grocery store pharmacy here gives them out for free, so it's pretty easy to do so.

I do as I am around people with suppressed immune systems for various reasons

Around a third of Canadians [1]. Although the statistics are a bit old.

[1] https://www150.statcan.gc.ca/n1/pub/82-624-x/2015001/article...

I do. It's free in Canada, just walk into any pharmacy and you're out in 10 mins.

I and most of my siblings try to get it every year.

It's recommended for anyone with frequent contact with children.

The solution is to use a harmless strain that has gene deletion(s). These sort of mutations are very unlikely to back mutate as the information has been lost from the viral genome.

The harmless strain doesn’t have to spread naturally better than the dangerous strains and it is likely any harmless strain would not spread better. We can artificially spread the harmless strain around so even if it is less contagious than the dangerous strain we tip the ecological balance in favour of harmless strain. This is really how an attenuated vaccine like the Sabin polio vaccine works from an ecological perspective.

The risk of the virus mutating is there right now. It is much less likely that a harmless strain becomes very dangerous than a dangerous strain become very dangerous. This would be a bigger jump in evolutionary space.

Ultimately as the immediate downvoting of my OP suggests this idea doesn’t appear popular. This doesn’t mean that it is not a scientifically valid approach that could work.

Maybe it happened like that, maybe it didn't. The Wikipedia page on the (possibly) zoonotic origins of SARS-CoV-2 mentions lots of questions and uncertainties, including whether the Huanan wet market was the source at all (because of the raw meat) or simply a place where infected people spread it:

https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr...

I'm not going to quote every paragraph casting doubt, but take a look at this (from Wikipedia):

> The first known infections from the SARS-CoV-2 strain were discovered in Wuhan, China.[12] The original source of viral transmission to humans remains unclear, as does whether the strain became pathogenic before or after the spillover event.[18][57][15] Because many of the first individuals found to be infected by the virus were workers at the Huanan Seafood Market,[58][59] it has been suggested that the strain might have originated from the market.[15][60] However, other research indicates that visitors may have introduced the virus to the market, which then facilitated rapid expansion of the infections.

Note that "facilitating rapid expansion" may simply mean that because it was a place with a lot of people grouped together, the infection could have spread more easily -- the reason we need social distancing now -- but it doesn't automatically mean it has to do with raw meat of exotic animals.

Now, it can be the problem is raw meat after all! But it seems to me research is still ongoing about whether this was the real culprit. That's all I'm saying.

I'm unconvinced that minimizing contact with raw animal meat markets -- in what you call "the lowest hanging fruit" -- would "fix" the problem with these kinds of pandemics. Not until we know they are the major factor in spreading the infection. Maybe it would help, or not, but "fix"?

Note I'm not disagreeing better sanitary conditions are desirable. I'm disagreeing -- or rather, casting doubt because I'm unconvinced -- that [quote] "we will continue to see pandemics until unsanitary practices like wet markets with exotic animal products are outlawed".

If there is a firm conclusion that this was indeed the major factor, sure. My comment was that, according to articles linked to from Wikipedia, the jury still seems to be out on this.

> but whether it, and similar markets significantly increase the chances of a similar event in the future.

I’m not defending wet markets but on that theory we should also ban all pets. And ban all livestock. And ban all hunting and eating of hunted meat.

> Excessive hand washing among the people who do isn't gonna help a lot particularly in drought-prone areas.

I am a European who has been living about 100km north of Western Sahara for a few years now: People here wash hands much more often than Europeans or US Americans and they know how to do so using much less water. More often than not, in restaurants, with European guests, I have to point out that "I am going to wash my hands" before eating so that everyone does it - despite locals and me visibly having done so when entering the restaurant (that all have facilities to clean your hands in the dining room or directly at the entrance).

In Berlin, for 15 years I was pissing people off by pointing out they did not wash their hands after using the restroom. Pro tip: Wait until they are back at their table and then congratulate their friends on having such a close group where nobody minds sharing a bowl of peanuts with the guy who just did not wash his hands...

> I don't think it is a bad idea to keep looking for ways to prevent these outbreaks as close to whatever their origin is as possible.

Not at all, but let's not forget that these markets are the only ones in a lot of places. People rely on them for food and income: Where I live the next proper supermarket is a 2.5h drive either north or south. People from small villages walk to the closest souk (market) once a week to sell their goods.

Furthermore, whenever people in the first world blame "unhygienic wet markets" that sell "exotic food" I am very careful:

* What's exotic for a US-American might be a staple for someone else;

* What the tourist buys might be something the same vendor would not dare to sell to locals (but tourists leave after a few days, so no impact on the customer base);

* Preparation matters: Down here meat is always well done and vegetables are always cooked to death. Notable exceptions: tourists who explicitly order meat medium or medium rare.

So, given that the markets are essential for the locals and that we 1st-world citizens cannot maintain a decent hygiene, I still think we should start with ourselves before banning "exotic" behaviour.

From what I understand you build some resistance as you are exposed to multiple variants of the same flu virus so it's quite possible this would hold for coronavirus making refection less likely to lead to a severe infection.

Lets also not forget that there is likely to be well studied effective anti-virals at some point like we have for the flu today.