Recovered virus patients retest positive due to 'dead' virus fragments: experts | Hacker News Reader

Recovered virus patients retest positive due to 'dead' virus fragments: experts

m-en.yna.co.kr

237 pointslsllc237 comments

It's interesting, and somewhat reassuring that they mention people recovering from the hospital after two months, as I believe I've had coronavirus symptoms for about 6 weeks now without much change. My symptoms have never been quite as severe as the last time I got the flu, but they show little change over time. Lethargy, sore throat, pink eye, and mild fever are the primary symptoms for me. I'll feel 95% better, then go for a walk and relapse for another week and a half.

I noticed exactly the same dry cough, itching eyes, laziness and feeling tired symptoms as you. Don't know If i'm positive, but I remain at home, avoid contact, and wash the hands often, just in case.

Flu-like hitting hard in December or so (before the start of the problem), and ripples all the way since that. I don't know if is coronavirus or other thing, but the recurrency of the symptoms is puzzling. Could be just a spring allergy also of course. No fever at all.

I had a good sweat for half a night followed by a dry cough that lasted about 4 weeks from late February through March. It's gone now but I don't remember the last time I had a cough last that long. Once the antibody tests are more widely available I plan on taking one to understand if it was covid19

FYI, you can buy yourself an antibody test online directly from Quest Labs for $119.

That’s great news; here’s the link:

https://questdirect.questdiagnostics.com/products/

However, I’m disappointed that it’s not available in the states of AK, HI, OK, AZ, IN, nor outside of the U.S. Further silliness is that in CA and OR you have to wait a week to get the results because California and Oregon state laws require that lab results be held for 7 days before Quest can release them; this hold is in place so that your physician has the opportunity to discuss your lab test results with you prior to you receiving them.

Another annoyance is the little questionnaire you have to go through before they agree to sell it to you. You have to divine their intentions for each question. If you don’t answer “correctly”, this is what you get and they won’t sell it to you:

This test is not right for you. Based on your response, you may still have an active COVID-19 infection and this test may not be right for you at this time. COVID-19 Immune Response testing is specifically used to check for an immune response to the virus which can take time after an active infection.

I understand all that. I just want to buy the test. Maybe I want to keep it for a day when I or someone I know needs it. Or whatever reason. Why force users to reverse engineer the questions and then lie to get it?

Also if you give your date of birth as less than 18, you get the same “This test is not right for you” refusal. I guess they don’t want to sell to minors, though the message is deceptive since it has to do with regulation and not whether the infection is active. So if you’re buying it to test your children, you again have to lie to their questionnaire since the questions are posed for the person taking the test.

The bureaucracy surrounding medical products is just horrible.

Why do you feel that anyone is entitled to buy their test even if they do not meet their criteria for who they believe should receive their test?

A test is not a life-saving device, especially for a test that only detects recovered patients.

If it started in December, it's probably not covid 19. If you don't have a fever, it's probably not covid 19.

The official record has traced the first case back to November 17, so it definitely seems at least possible it was spreading earlier than we know.

2020, the year COVID outranks Cancer as the webs goto diagnosis for anything and everything

I saw a report today that said most people going to hospital with covid-19 don't have a fever.

I don't remember if it was on december or january, honestly, but it was before the wuhan market jumped to the newspapers.

All tested members of my family were negative so far, so probably more around Jan than Dec, and probably not corona. Maybe just fungus spores or pollen

At the start physicians insisted on fever being a core symptom, but since then they have eased off on this. No fever does not mean no covid.

probably but not completely discountable.

its because people have been saying "hey what about this" despite the loud banging of the scientifically minded people yelling "NO EVIDENCE THEREFORE ITS AN ABSURD IDEA" that we know of a community spread case in the US that died on February 6th. Instead of a travel related case that died on February 29th.

so then was patient zero in US from travel on January 15th? January 1st? December 15th? December 1st? How many hops are really necessary

If patient died at Feb 6th, then it contracted covid about 1 month before that from somebody else, so Jan 1st, maybe.

I was going with 3 weeks, but yes early January like 2nd week 6th - 12th

and if that person was also community spread or travel spread then we are looking at mid-december either way.

> If you don't have a fever, it's probably not covid 19.

If you do have COVID-19, you're statistically more likely to not have a fever than to have a fever.

From what I've seen online, a ton of people in the US got hit hard in December, myself included - I typically don't get sick. Even if covid19 hadn't happened I think this would've been a bad flu year.

An anecdote about allergies. I take zyrtec (generic) for mild hayfever. Have been for almost a decade. So, I sort of figured I had allergies covered. I’d get cold/flu symptoms twice a year at roughly the same time each year, and just figured it was the seasonal flu (especially with school age kids, you get it all). I finally realized a couple years ago, though, that that most of the symptoms disappeared once I got to work, with it’s recycled and filtered AC. It took a long time to put this together since I’d tend to stay home when I thought I was contagious. So now I’m more aware of when the trees near me are dumping pollen, and it definitely lines up.

I say this to let you know that if you’re stuck at home, you may be more likely to be feeling the effects of local allergens that you might not feel if you spent less time at home. The symptoms you describe sound a lot like allergies to me. I’m not a doctor though, so please do your own research. And talk to a doctor about the symptoms, especially if they progress...

3M sells some high-quality home HVAC filters under the "Filtrete Healthy Living Advanced Allergen Reduction" label; you may want to try one for a couple of months and see if it helps you breathe better. They make a difference for me versus run-of-the-mill filters. I'm sure there are better ones out there, or cheaper ones of equal quality from a different brand, but in my experience these work quite well.

My story is that at the end of October I flew from SFO and on the way home I felt sick to my stomach (probably food poisoning), but about 5 weeks later in December I was having some pretty severe breathing issues, like it was cut in half and no other symptoms I could identify. It was attributed to anxiety by my doctor and a few days later I felt okay. Then at the beginning of the year in January it hit again and has been hitting me on a monthly cycle with diminished severity. In fact I’m feeling it again today after feeling totally fine for weeks. I don’t know if its Covid because I was never tested for the disease or the antibodies but it was And is a strange feeling unlike anything I’ve felt. Like wearing an extremely tight turtleneck. I wonder after reading these accounts if this disease is a chronic illness that lives in your circulatory system. Is there anything known about this?

Sounds like we had a similar respiratory disease. I also flew through SFO, like many millions of others, in December. I fell ill over the holidays, and then again in January. I also rarely fall ill, and hadn't had a cold or even severe allergies for several years.

My primary symptom was respiratory, I could go up a single flight of stairs and feel short of breath, like someone was standing on my throat and lungs.

I saw my doctor a few times about it, but neither my partner, nor my family, nor my co-workers fell ill. The phylogeny that I've seen published about SARS-CoV-2 definitively rules out that I had it. Likewise, if I did I'd expect that based on how virulent covid-19 is, I'd expect someone else I know or one of my grandparents to have caught it.

I've seen similar reports of a respiratory illness on Twitter and I think it comes down to a uniquely bad flu season and perhaps some other bug going around which hits the respiratory system.

Yeah, that's just the flu or some other disease. It's a bad flu year.

If it was actually covid-19 community spreading in December, then we wouldn't be talking about a few thousand deaths now in April, we'd be talking about millions. The exponential curves don't match up.

Whatever you had, it wasn't covid-19.

> If it was actually covid-19 community spreading in December, then we wouldn't be talking about a few thousand deaths now in April, we'd be talking about millions.

That's assuming the death rate is as high as it is estimated from known cases. If the actual death rate is a magnitude smaller due to huge amounts of undocumented cases, then the curve is wrong.

Going by some of the antibody tests performed, this seems to be the case, but the antibody tests might be erroneous as well.

There's a strict lower bound of around 0.5% on how mild the IFR can be looking at NYC and Italy

https://www.medrxiv.org/content/10.1101/2020.04.18.20070912v...

There's absolutely no way that it's been running rampant since december

Hell no. That estimate comes with many assumptions, so unless you are willing to list them all, it is better to just provide the link. And it is still just one study, waiting to be proven / disproven. Take it easy and use common sense.

This is actually quite common in COVID-19 and SARS patients, Chris Cuomo from CNN popularized the "waves" that it comes in with his personal ordeal. Some evidence that this virus either replicates very fast, or hides from the immune system (could explain the asymptomatic people) until the right moment when you feel weak after a workout. Eventually your body will 100% defeat it, but you should probably take it easy and socially distance until you have 72 straight hours without a fever.

This is common in Chickenpox too, where it hides out and then re-emerges later in life as shingles near the age where your immune system starts to weaken.

Good luck, you'll get through this.

If this person has COVID-19, should they not socially distance with extreme vigilance for a very long time?

I must be misinterpreting you, are you really saying you'd be comfortable being around people right after peak symptoms of a COVID-19 infection?

parent is using CDC guidelines (I think?). I agree with your take, however.

Yeah, those were (and maybe still are) CDC guidelines:

2 negative tests at least 24 hours apart OR

7+ days since symptom onset, AND 72+ hours without fever (with no meds) AND significant improvement in respiratory symptoms

There's mounting evidence that people are no longer infectious from day 8 after symptoms first appear onward. A German study tracked only a handful of patients, but tracked them very rigorously, with multiple swabs each day for 30 days and were unable to cultivate a live viral isolate after day 8 in ALL cases, even when the patient's viral load was still extremely high. (But in fairness, a bunch of viruses work this way, where patients are still sick and their viral load is high, but they cease being contagious after a few days. Eight days is still a long time, but you shouldn't have to quarantine for a month, we hope.)

Do you have a link to the study?

For those who wonder, it's a preprint[1].

[1] https://www.medrxiv.org/content/10.1101/2020.03.05.20030502v...

> hides from the immune system (could explain the asymptomatic people) until the right moment when you feel weak after a workout

I'm pretty sure this is what happened to me. I felt fine, did a big workout for the first time in a few weeks, and a few hours later, came down with a low grade fever, which progressed into an illness that very closely tracked the symptoms and timeline of COVID-19.

The good news: I was recovering in a house with my two parents around age 60, and my younger brother. I spent most of the two weeks in my room, trying to avoid any contact, and nobody else in the house got sick (it's been over a month since I recovered, so we're pretty confident of that at this point). So, it's not inevitable that you'll transmit it if you take distancing measures early!

Have your two parents and younger brother had a particularly big workout yet? ;)

Both the parents have, at least! My dad and I did a 35mi bike ride last weekend :)

Unrelated, but that fake, dramatized departure from quarantine that Cuomo did really bothered me.

He was leaving his home well before that, violating doctors orders. It made me question how much of his "ordeal" was dramatized as well.

I don't necessarily blame him: CNN producers are likely at fault.

Is there evidence of that? I remember him claiming he hadn't left the basement at all. Also, I know you can't tell by looking, but he never really looked all that sick. Never a stuffy or runny nose and usually not that tired looking, no red face, no watery eyes, etc.

I have no reason to doubt his account, unless of course there is evidence that he didn't stay down in the basement that whole time.

You mean more evidence than Cuomo's own account of him being outside his residence that he gave on his radio show?

what? that's a far different thing from gp's claim

The account Cuomo gave was of a confrontation he had because a cyclist who knew from CNN that Cuomo had COVID19 and was quarantining asked him what he was doing outside in public around his family. It wasn't close to his property. He was violating quarantine.

He didn’t stay in the basement. He was “caught” outside with family members and no mask.

Look up the “fat tire biker” incident.

For obvious reasons CNN is not admitting that the basement emergence video was entirely fake.

Personally I now think that Cuomo did have Covid but probably had mild symptoms and was basically soft-forced into hamming up the symptoms to “drive the reality of Covid home” to America.

I hate to use the term but CNN is truly fake news at this point.

I posted a New York Times opinion-piece a little while back on a woman who created an online support group for people recovering. I found the article because I was looking for some info myself on how long to expect things to last. I was feeling pretty down because it just seemed to linger and linger. Made me feel better to know this was common. The official CDC guidance broke people into groups of “mild” and “severe”, with corresponding time to recover. But the anecdata suggests even “mild” (I.e., didn’t go on a vent) can have lingering symptoms for sometimes as long as 30 days. Hang in there!

The 30+ day group has now 1600+ members.

I'm on my 8th week, and some people are on 60+ days.

What's amazing is the wide variety of symptoms.

The original article: https://www.nytimes.com/2020/04/13/opinion/coronavirus-recov...

thanks for this. Have nearly identical situation. 2 days shy of 6 weeks. The fatigue/lethargy is probably the worst part.

Also, I tested negative 5 weeks ago, but given issues with testing, I have self-isolated anyway.

edit: never have found a fever, though i had pretty intense bouts of chills in the first week

Same feeling here, but I can definitely attribute this to an allergy. Go and see a doctor and get an allergy test done, I had similar breathing and lethargy issues in last year November already. Then nothing until end of February and since then it is on and off for days.

I live in Berlin and we had very long periods of dry weather, yesterday it rained properly and I can immediately breathe again.

People are self isolating without symptoms, but you go for walks?

Lots of places have a rule that you can go outside for one exercise walk a day provided that you stay 2m away from people.

I'm not saying it is against the rules, but what should be common decency. People going to the office having a cold don't break any rules, but the lack of self awareness is usually frowned upon.

Catching, or transmitting C19 outside looks to pretty unlikely https://thehill.com/policy/healthcare/494348-new-study-finds... May turn out that the best prevention advice would have been to stay outside as much as possible.

Most of us only go out for the bare minimum, but people actually experiencing symptoms are going for a walk. This does not add up. Exposing others knowing fully well you are having symptoms is not right.

I fortunately was stocked up on supplies for the first 10 days of symptoms (after which I thought I had recovered but still was quite careful). However I don't have the luxury to stay inside for 6 straight weeks at a time, nor would it be prudent for recovery and good health to be deprived of fresh air for so long, in my opinion. Of course I am still quite self isolated even when I do venture out, use a disinfectant wipe to touch doors, wear a makeshift mask, hold my breath and cross the street before passing other pedestrians when I walk, and manage to not come in close contact with anyone.

And I am far more careful than most, including the person I believe I contracted it from, and I have still possibly exposed some people incidentally. This is why I believe that any idea of containment and contact tracing is absurd in any semblance of a free country, and the only way the pandemic ends is if everyone gets it or an effective vaccine is developed. However, almost everyone will probably get it before the vaccine is developed.

> I've had coronavirus symptoms for about 6 weeks now without much change

I've been having a mildly sore throat for five weeks, with a couple of days of feeling unwell, and slightly elevated temperature (not fever) on occasion. No cough, but a "you're about to get a cold" feeling in the airways. I've had also had one "relapse" last week. Since I didn't have any "hallmark symptoms", I didn't qualify for a test.

If I really did contract COVID-19, it must be highly contagious, because I've been drastically minimizing going outside even before there were any cases recorded outside Asia. I'm also obsessive about washing my hands and not touching my face. I haven't had a cold in five years and have no allergies.

That's interesting.

I've had very mild but puzzling symptoms since late January when I returned from Thailand/Malaysia.

Sometimes absent entirely for a week or two and sometimes as strong as that "oh - I'm beginning to come down with something" feeling. Sore throat is common as is a slight heaviness in my chest.

Tends to come on in the afternoon and usually imperceptible in the morning.

It's only a nuisance if it wasn't just enough to trigger anxiety about whether or not it was Covid-19.

I've dismissed the idea that it actually was Covid-19 because I've never heard anyone say that it could last this long but it's definitely unusual.

EDIT - for various reasons I've been strictly isolating for almost 2 months anyway. I would have isolated earlier if the advice had been clearer.

That's pretty much my experience in terms of symptoms. I otherwise haven't had any cold symptoms whatsoever in the past five years. I'm waiting on reliable antibody tests to become available.

An acquaintance of mine told me of a friend that had died of viral pneumonia at the end of February, when there were very few cases identified in the west. Strikingly, he reported a loss of taste and smell.

The annoying thing is that I'm now isolating both because I might not have had it and because I might still have it.

Thank you so much for posting this. I was in Boston in early March on a business trip, two days later I began having a sore throat in the afternoons/evenings that was gone again every morning. After four or so weeks, it finally disappeared, only to come back strong for two days, where I thought I was finally coming down with something, then it turned mild again, then disappeared. The sore throat went on for at least six weeks, which is easily three times longer than anything I've had before in my life.

I wouldn't have thought it was COVID-19, except for the new studies from Spain regarding skin conditions. I had what I thought were horrible bug bites that appeared one morning. They were very itchy small blisters, and I thought I had bed bugs. I hired an exterminator, but he found nothing at my house. What I had - exactly 14 days after my trip - matches exactly with descriptions of skin rashes written up in the study. I'm 53 years old and the study mentioned this kind of rash was most common in middle-aged patients.

So . . . now I'm convinced I had/have it, and will get an anti-body test when they are available.

This has been hypothesized for some time, as it is a phenomenon seen in other respiratory viruses (indeed in other viruses in general) where your test is detecting a fragment of virus. These fragments persist after clinical recovery, and, combined with imperfect sensitivity/specificity of your test, can show a pattern of "re-infection": positive test during illness, negative test during/after recovery, then positive test again later.

The gold standard (sort of) for whether the actual virus is there is isolation and "culture" of virus from a swab using, say, a petri dish. But unlike (most) bacterial pathogens, this process is laborious, requires actual relevant cells (many bacteria just grow in goop like Agar) and is slow. (Alternatively you could just try to infect someone else! And if that second person can subsequently infect someone else, then you've shown the virus was there in the first person. And the second person. Sorry, second person.)

Empirically in hospitals we've been seeing a couple of patients retest "positive" but haven't seen any get sick or re-hospitalized, so that's also reassuring.

As far as I can tell, this paper from Germany actually took the time to detect live virus vs PCR positive: https://www.medrxiv.org/content/10.1101/2020.03.05.20030502v...

They found that, for all patients in the small study (N=16), none tested positive for infectious virus after day 8 post-onset, despite testing positive for the virus in RNA over 2 weeks after illness onset. This, to me, is encouraging.

Is there a better source for this than a report of a press conference? Like, a paper? The KCDC is highly competent, and maybe the English-language Korean press isn't as bad as the US press ("Is this going to be a deadly pandemic? No." "The flu killed more people." "Healthy people wearing masks doesn't help.") but I really have no way to judge. And I've been burned too many times this year already by trusting the ignorant dabblers we call journalists.

To learn more about coronavirus, treatment and vaccine development from the perspective of doctors in S. Korea, try watching these interviews in order. Each is about 30 - 50 min long. I posted the links and the dates they were uploaded. The videos are excellent because the doctors are not interrupted with questions.

1) 2020.03.27

1st interview with Professor Kim, leading expert on coronavirus in Korea. In Korean with excellent English subtitles.

https://www.youtube.com/watch?v=gAk7aX5hksU

2) 2020.04.14

2nd interview with Professor Kim, leading expert on coronavirus in Korea. In Korean with excellent English subtitles.

https://www.youtube.com/watch?v=QwoNP9QWr4Y&t=1081s

3) 2020.04.25

Interview with the Director General of the International Vaccine Institute (IVI) about COVID-19 Vaccine. It's in English.

https://www.youtube.com/watch?v=5cYWd0N8nO4&t=120s

4) Note in the interview with Prof Kim uploaded on 2020.04.14, they were still not sure if a recovered patient testing positive again was due to reactivation/reinfection or not. They were still trying to confirm it as of 2020.04.14.

But it seems the yna.co.kr article posted on 2020.04.29 confirms recovered coronavirus patients may have tested positive again due to traces of virus fragments that have been inactivated.

5) I'm hoping the Youtube channel will upload another interview with Prof Kim about covid-19 soon.

Interviews with doctors are interesting from a human empathy perspective, but I really want to be reading papers, not watching interviews, and I want the papers to be by epidemiologists, not just doctors.

Have you watched the 3 interviews? I'm not picking a fight nor judging. Just curious. I called them interviews but really they are like lectures in my opinion. The doctors speak most of the time.

I'm not a doctor but I figure doctors are too busy collecting/digesting data to publish quality papers? Especially when new data is being generated at a fast rate?

There is an issue of many research papers covering Covid-19 not getting enough peer review before being made available to public and covered by news media.

Prof Kim's called this a "Thesis Pandemic", a flood of Covid-19 related research papers being put out by researchers that get covered by new media before they are peer reviewed. And apparently many of the papers are made public by the researchers without enough data to really back up their thesis.

Because the virus is so new, there is really not enough data. And the researchers are doing their best to help with finding treatment, but apparently many of the papers are not peer reviewed enough before being picked out by news media to be covered.

I did google and found a few reading material below but not sure if it's what you are looking for.

https://wwwnc.cdc.gov/eid/article/26/6/20-0251_article

No, I haven't, because I don't want to spend my time watching videos; not only are they agonizingly slow, they are also a medium actively hostile to quantitative data and critical analysis, which is perhaps why the news media is so fond of them. (I don't want to pick a fight either, but I sure as hell am judging!)

Everything you say is true, except that mostly doctors are not busy collecting data, but rather treating patients.

You may have intended to link a different paper; the one you linked is about Gansu in China, not Korea, and does not mention rt-PCR, false positives, viral RNA, or reinfection or recurrence. It does mention "secondary infection" and "secondary cases", but, as it explains, that means people who were infected within the study region by other people ("indigenous"), rather than coming into the region from outside ("imported").

1. Googled "Korea University Medicine covid-19 papers" and found below 2 links. Professor Kim in video 1 and 2 is from Korea University.

https://www.medrxiv.org/content/10.1101/2020.03.15.20036368v...

https://www.sciencedirect.com/science/article/pii/S120197122...

2. Also found below link on cnn.com

https://wwwnc.cdc.gov/eid/article/26/8/20-1274_article

Yah my quick search didn't return much on papers discussing false positives, viral RNA, or reinfection or recurrence. I'm guessing it's too new for formal papers.

I should've said doctors are busy treating patients and researchers are busy collecting data.

3. But I did find below article posted 12 hrs ago

https://www.independent.co.uk/news/world/asia/coronavirus-so...

South Korean expert panel has concluded that dead virus fragments were the likely cause of more than 290 people in the country testing positive after recovery for coronavirus.

4. The 2 videos with subtitles can be consumed fast if you skip forward a few seconds at a time as you can read English subtitles. Commenters also posted helpful summaries so you can get to just the topic you are interested.

Maybe, the following research papers from germany's top expect on Sars-Cov-II are interesting to you: - https://www.nature.com/articles/s41586-020-2196-x?utm_source... - https://www.nature.com/articles/s41564-020-0695-z

and his latest article, on Twitter yesterday: https://zoonosen.charite.de/fileadmin/user_upload/microsites...

He is also doing a podcast with already 37 episodes about Covid-19, but it is only available in German. But the German transcripts contain links to articles he discusses. And those are articles he deems good enough to discuss them in public, even though they are often just preprints. https://www.ndr.de/nachrichten/info/Coronavirus-Update-Die-P... -

While these three papers are indeed good and valuable, they do not seem to mention Korea or touch on the question of why, and how often, rt-PCR tests continue to return positive after remission of symptoms, and in particular whether these apparently reinfected patients are contagious. I am not sure why you mentioned them.

So I assume they're using a cheaper ELISA test to look for IgG/M first if the patient is known recovered or asymptomatic, but then how could rtPCR protocols create false positives transcribing viral RNA unless the primers, probes, or matched regions are too small? Are they matching un-encapsulated RNA fragments?

Is there the a type of in vitro protocol for measuring viral infectivity potential of a sample?

Yes, you can cultivate the right human cells and infect them. I suspect this kind of thing would be restricted to the highest security laboratories, because you’d be actually multiplying the virus in its infectious state.

Does anyone know when the contagious period (for a single covid infection) tends to end? Are you contagious the entire time you have symptoms? Beyond that point? ("Viral shedding" doesn't necessarily mean contagious.)

Diane Havlir Professor of Medicine and Chief of the HIV/AIDS at Division at UCSF gave a presentation where she said they can't culture virus 8 days after symptoms. And that viral fragments can be detected for weeks.

Source: https://youtu.be/bt-BzEve46Y?t=435

Thanks, that's interesting. Given an infectiousness period, it seems you can relate R0 to doubling time.

Like, if R0 is 2, that means each patient (on average) infects 2 others, but during the period of time they are infectious. So that would mean 2 others over the course of 10 days (8 days post-symptom, 2 days pre-symptom).

Someone else either in this video or one of the others they said viral shedding in COVID19 is a 1000 times higher than SARS. There is a paper up on the CDC website that estimated r0 between 3.8 and 8.7, which is much higher than initial estimates. Matches the observation that in crowded indoor locations (nursing homes, prisons, homeless shelters, cal centers) everyone becomes infected within days to a week.

UCSF's grand rounds on covid19 go up every Thursday. Upside, high quality distilled information. Downside, hour and a half long.

This is excellent news.

We knew this for about two months, and now they are posting it on April 29. These PCR tests are overly precise and pick up dead bodies of RNA chains of length 600. The whole chain is 32K. But when cut into pieces by the immune reaction it's still being picked up and falsely flagged as active. So people were falsely worried that they could get reinfected and infect others. Those claims constantly showed up on fake national news.

But ...

Are those fragments still able to transit from person to person (through whatever route), and might your immune system still react to it and then sicken or kill you?

The fragments are inactive so no.

No. The RNA fragments must be encased by a lipid "bubble" with the spike protein receptors in order to invade and replicate within your cells. Even if you somehow injected these fragments directly into your bloodstream, your immune system and kidneys would easily destroy these waste particles and flush them out because they are not replicating. They're essentially the 'dead carcass' of this virus.

yay:

> The committee further said it is virtually impossible for the virus to be reactivated unless the COVID-19 virus causes chronic infections.

> "The COVID-19 virus does not invade inside of the cell nucleus and combine with a patient's DNA," Oh said. "It means that the virus does not create chronic infections."

> Oh further said the COVID-19 virus is different from diseases such as HIV and hepatitis B in which the virus stays dormant inside of a cell nucleus and later causes chronic infection.

I wonder if this gets the CNN headline treatment like the original story did...

good news ... i think then vaccine will work?

In other words, when you recover from covid-19, you are immune to it. In other words, covid-19 is just like every other virus, in this respect.

Governments around the world have reacted with terror to this pandemic, but that doesn't mean the virus is some sort of strange monster. It's extremely infectious, and somewhat more lethal than influenza. That's all.

When I first heard about those patients who had recovered from the virus, and yet were still testing positive, it felt like a mistake. I'm glad it's been cleared up.

In other words, when you recover from covid-19, you are immune to it

How does this follow?

That's how immunity against pathogens usually works. There are exceptions like the flu which mutates into sufficiently distinct strains that the immune system doesn't (fully) recognize. I'm still oversimplifying here.

Well viruses in general, AFAIK, mutate - and that's how we trace their movement through the infected: you sample the virus and look at the mutations eg https://nextstrain.org/ncov.

Do we know for sure that Covid19 in N.Europe isn't sufficiently mutated over that in Australia, say, that secondary infection is possible (even if recovered people's antibodies recognise it somewhat)?

We don't know much for sure.

What I've heard from experts in the field, but I don't have sources, is that the type of RNA virus is different from influenza and doesn't mutate as quickly - which is potentially good news for those hoping for a vaccine.

I think it's an overstatement. When you recover from it, you don't still have it, even if you test positive. That means that at least some of the "got it a second time" reports are false.

Are they all false? Don't know. There's hope, but not yet evidence, so far as I know.

What evidence are you using to show people have recovered who are still testing positive? What confirms that the positive test is false?

Can you provide some sources?

Is this a joke? Literally the article at the top.

No, not a joke, you seemed to be talking from a general perspective rather than "in the results in this particular PCR test in South Korea". As if you had generally applicable information.

My understanding was there were many different tests being used ... so on what basis are you making that generalised statement.

> When you recover from it, you don't still have it, even if you test positive. //

A plausible explanation for specific tests doesn't make this a universal truth; so presumably you are relying on more information? Also, there being an explanation for positive tests based on dead virus, doesn't mean all post-infection positive tests are due to dead virus; that's a massive assumption.

He is right, people may be testing positive just because of dead virus fragments, but to say they have fully recovered there must be no virus alive in their bodies - lack of symptoms may suggest it, then having antibodies may guarantee that eventually..

.. assuming the virus can not hide (and be able to leave) where they can't penetrate - like in the eye ?

.. and with weak immune system the outcome may be (how?)long undecided as the antibodies are not being able to fight the virus fast enough to finish it definitely?

> Are they all false? Don't know. There's hope, but not yet evidence, so far as I know.

You mean there's evidence but not proof.

That doesn't strictly follow.

Here is the thought process, though. Typically when you get an infection, your body builds antibodies that can attack the pathogen. The next time the pathogen shows up, your body kills it before you get sick. This immunity doesn't always last for a lifetime, but there is pretty much always some immunity. With COVID-19, early reports showed that this wasn't happening; people got sick, recovered, and then got COVID-19 again. What the news article says is that the test was wrong; when they tested positive the second time, the test was just returning incorrect results (because of limitations of the PCR technique; it's testing for certain RNA, not for the existence of an infectious live virus).

So to say that this means you can be immune to SARS-CoV-2 is not strictly correct. What it says is that there is no reason to think that this virus is any different from many of the other viruses that we already know about. (We do know about viruses that you can't be immune to, like HIV. But those viruses explicitly attack the immune system machinery that is supposed to kill them. We have no evidence that SARS-CoV-2 does that.)

We also know that immunity to coronaviruses generally declines rapidly. We have no idea how long somebody is immune to Covid-19 when they have recovered.

It doesn't strictly follow, you're right. But this punches a huge hole in the already kind of surprising/unlikely possibility that we had suddenly just discovered the first (or if I'm wrong, "a very rare") virus that can re-infect the same person with the same strain.

In at least two ways I can think of. First, these fragments have been inactivated, probably by the immune system, suggesting you have some immunity (obviously, that's not the same as being perfectly immune). Second, given how infectious the virus is, the fact they're not finding genuine positive re-tests strongly suggests some immunity is happening.

How would you recover at all if your body weren't producing antibodies capable of killing it?

>in other words, when you recover from covid-19, you are immune

Well, it may appear to be the case so far but afaik that hasn't been rigorously confirmed, and this article doesn't imply immunity to live virus upon reexposure.

>but that doesn't mean the virus is some sort of strange monster

Except there are dozens of papers being publishes about a range of effects - damage to a multitude of organs, virus fragments found in brains during autopsy, high incidence of clotting/stroke. By many SME accounts it is very much a strange monster. Also recall the documented rapid progression from asymptomatic to dead.

>It's extremely infectious, and somewhat more lethal than influenza

So one of these numbers (CFR) is about the same, but the R0 is anywhere from 2-4 times larger, and the critical rate appears to much higher than the typical flu. So the response of "terror" isn't totally unwarranted.

>When I first heard about those patients who had recovered from the virus, and yet were still testing positive, it felt like a mistake. I'm glad it's been cleared up.

Agreed. And another reinfection case occured in an immunocompromised patient. So it's looking like the infection doesn't become chronic or dormant.

> somewhat more lethal than influenza

My understanding is that most evidence points to order of magnitude more lethal even when the hospitals aren't overflown.

Regarding "testing negative then positive" the experts already expected that there were no real reinfections.

> My understanding is that most evidence points to order of magnitude more lethal even when the hospitals aren't overflown.

If those mortality estimates were based on the number of positive test cases, then they're very likely overblown. Recent seralogical studies indicate that the number of positive test results are likely a small fraction of the total number of cases, and likely the most severe subset at that. None of this is to say that it's less lethal than influenza, only that the situation is developing rapidly and any given mortality estimate may well be outdated.

In any case, we can all agree that regardless of the value of the number, its "way too many fatalities". My family has lost several colleagues/classmates already. This did not happen in other years. This year is very different, and concerning.

I'm terribly sorry for your losses. It's an awful disease, and loss of life is terrible. It is indeed concerning, but if we can understand whether these fatalities are due to high morbidity or "simply" because it is highly contagious, we can make better decisions about treating the disease, setting policy, etc which can all drive down the amount of suffering and death. That's perhaps a small consolation to those who have lost friends and family already. :'(

My understanding is that the current estimated IFR from those studies (NY specially) is between 0.6% and 1.2%. I think flu is around 0.1% (however I am not sure if that is the CFR or the IFR). The second factor to consider is the attack rate, how many people are likely to get infected. For flu is around between 10% to 15% of the total population, while for Covid it is, potentially, larger than 80% (no natural immunity and no vaccines). It is however unlikely that it will reach that level given the current containment and mitigation measures. But if it reaches something like 40% (double of the latest NY estimate), it will mean covid is between 16 to 48 times deadlier than the flu.

Yes, sorry, I thought we were comparing IFR and not CFR.

No worries, I had made the same mistake. I just wanted to point out that the attack rate is also part of the fatality equation, and it is commonly not taken into account.

I believe 0.1% is the CFR for the flu, and the IFR is close to 0.04%?

Thanks. I have seen serious estimates of 0.1% CFR for the 1957 and 1964 flu pandemics, but only notes saying that the seasonal flu CFR is <0.1%. Do you have a source for the 0.04% IFR?

No (hence the question mark), I'm seeing 0.04% pop up everywhere but I haven't found the source for the number.

But it seems plausible if the CFR is <0.1% as there are both asymptomatic cases of the flu and people don't always go to the doctor even if they have symptoms. It seems like caring about IFR was rare before this pandemic and the lockdown

Got it. Thanks. I think it may be because the IFR is less reliable, since for most diseases it requires a gross estimation the real number of infected persons. It is probably more popular these days because people are putting a lot of effort into the comparisons with the seasonal flu.

IFR for flu is less than 0.1% according to the CDC.

https://www.cdc.gov/flu/about/burden/index.html

That's not the IFR since they're not counting asymptomatic cases (based on a quick read)

They don't mention IFR anywhere as far as I can see

> Recent seralogical studies indicate that the number of positive test results are likely a small fraction of the total number of cases

No: the antibody tests were done with the expectation that the total number of the infected would be much higher. The tests have such false positive rates that with the results actually observed the tests in most of the cases say nothing -- in most of the locations the numbers would be similar even if nobody would be a real positive. And there where the results are above these "noise" thresholds we also have a big numbers of deaths which do confirm my claim of order of magnitude deadlier than flu.

Even observing the pure death statistics we can see that, even in spite of all the measures actively taken throughout the world. Without them it's obvious it would have been again the difference of some orders of magnitude:

https://www.euromomo.eu/graphs-and-maps/

See also here:

https://www.ft.com/coronavirus-latest

the "Death rates have climbed far above historical averages" graph.

Going by the death rates, it's definitely deadlier than any flu of the past five years, but not by a magnitude. Not even close.

Saying that it would've been a magnitude higher without any of the measures is pure speculation.

Well UK deaths from flu are about were 500 deaths per 66M for the most recent year of published cause of death statistics, which I understand (from a couple of papers on annual infection rates) represents about 500/13M infections.

Covid19 figures in the UK are 26,000 [hospital] deaths for 165,000 confirmed infections. Even if we assume the entire population is infected ... that makes it a minimum of 10x as deadly as flu. We're at a slowly falling ~5000 deaths per day; when care-home and other Covid deaths get added ...

I think perhaps you're down-playing it a little too much.

To reiterate the third/last sentence of my post, I'm explicitly not down-playing anything--I'm not asserting anything about covid WRT the flu, only cautioning against drawing conclusions based on potentially outdated information.

So? I haven't read any of this studies either, but I'd expect seralogical studies to likewise indicate that positive flu test results are a small fraction of the total number of cases, and likely the most severe subset.

We have decades of data about the flu--we pretty much understand its morbidity. We don't need to make guesses based on positive test results like we were doing with covid.

Your argument is invalid.

This is due to testing methods that undercount the denominator. Countries conducting random testing have yielded an IFR of about 0.4%. 4x deadlier than the flu.

You're comparing the IFR of the corona virus with the CFR of the flu

No it's not. The IFR of the flu is 0.1%. The CFR is higher. The Case Fatality Rate will always be higher than the Infection Fatality Rate. The people who present cases will be a strict subset of the people who are infected.

Early studies treated the Case Fatality Rate as the Infection Fatality Rate, by virtue of the fact that the only people getting tested were people with symptoms. Random testing in Germany has indicated that ~20% of the population was infected or has been infected, and the corresponding death rate yielded an IFR of 0.37%.

What's your source for the 0.1% flu number? People are linking to the CDC website which explicitly only looks at symptomatic flu cases. Which means it's NOT the IFR. The flu also has asymptomatic cases!

If you're talking about this CDC website, it does track CFR [1]. And as I said, the CFR rate is higher than the IFR rate. Several years the seasonal flu has a CFR above 0.13%.

Measuring IFR is inherently speculative, unless 100% of the population is administered a test with no risk of false negative or positives. In order to compare the IFR of COVID-19 to the seasonal flu, we'd need to use the same estimation techniques. I've only found a few experts that have done comparisons of IFR rates of the flu and of COVID-19. The most reputable source on this reported an estimated IFR for the flu of 0.04%, but also an estimated IFR for COVID-19 of 0.2-0.3% [2]. This is "many times deadlier" if by "many" you mean 5 to 8 times deadlier. This is nowhere near the multiple orders of magnitude deadlier that was reported initially (IFR rates of 2-3% and above).

1. https://www.cdc.gov/flu/about/burden/index.html

2. https://www.bloomberg.com/opinion/articles/2020-04-24/is-cor...

Thank you for the sources!

Initially you were implying that the IFR of the flu was 0.1% and comparing it to an IFR of 0.4%, this is what I disagreed with strongly

The bloomberg link you're giving is showing that the vast amount of randomly sampled serological studies are showing IFR of 0.5%-1%. And importantly, looking at how the random sampling has been done for each case and ranking by quality, >0.5% results rank at the top (he studies with the biggest sampling problems show the lowest IFR)

0.2-0.3% is by far in the bottom range of estimates

I think the data shows a pretty clear single order of magnitude difference between the IFR of the flu and novel corona. But I agree that >1% IFR is extremely unlikely

How, exactly are we ranking by quality? The only anti-body study that's been published in a peer reviewed journal has indicated an IFR ranging from 0.12% to 0.2%. The author did make note of these criticisms that the infected rate was over-counted, but even when using an infected rate of 1.5% instead of the paper's estimated 2.5% the IFR would turn out to be 0.33%.

Plenty of the >0.5% results have serious sampling problems of themselves. The Dutch study sampled people who were donating blood. The subset of the population that donates blood is could easily have different behavior than the general population: like being more health-conscious and thus less likely to be infected, which would inflate the infected fatality rate.

And when we compare against the flu, we also have to consider that there are different methods of estimating the infected fatality rate. More conservative estimates on infections of the seasonal flu yield higher IFR values. The epidemiologist being cited here is providing relative estimates of 0.04% and 0.2-0.3%. We could go with more conservative estimates on the infected rate for COVID-19, but we'd have to be similarly conservative when measuring the IFR of the flu.

I was ranking "randomly selected" higher than "people volunteering" (which was one of the main issues with the santa clara study, mixed with the test used being so imprecise the error bars were big enough to include a 100% false positive rate. That is by far one of the worst designed studies I've looked at, even if it has been peer reviewed)

I'm not sure the blood sampling would skew the direction you think it does, healthy individual could just as well mean that they're more likely to have had it since they're less likely to sit at home and stick to a quarantine. But you are right, it definitely counts as a sampling issue and I'll concede that ranking by quality is a lot less clear cut, I should not have been so confident

> unless 100% of the population is administered a test with no risk of false negative or positives.

Actually, the "risk" of false positives or false negatives is dependent on prevalence, 100% is not always required. If you have a test where 5 of 100 cases are false (i.e. 95% times is not wrong), and nobody of these tested is actually infected, you could incorrectly believe that 5% of population is infected even when nobody is, meaning such a conclusion would be completely false.

But if the population is actually already e.g. 50% infected, the same test can "lie" only 5%, giving you 47% or 53% but still being "mostly true" (from the engineering point of view).

So it is important to ignore the test reports as long as they are close to their false positive rate, which they were in a lot of antibody tests done up to now.

Also "false positives" and "false negatives" can lead to wrong handling of the cases, but that's another topic.

You found my favorite part of that whole comment. I hereby announce my support for redefining "somewhat" to mean "an order of magnitude" for all subsequent HN discussions.

Governments are reacting to a seemingly very high infection rate with a (best case from the numbers I've seen) fatality rate 10x higher than the flu and the inadequacy of healthcare systems to shoulder the burden all at once (which has more side effects, including more death).

Correction: the virus isn't some sort of strange monster in this particular aspect. Have you seen the reports of blood-clotting problems? Sudden deaths from people who'd shown no symptoms? There's still a lot that's weird about this disease and we have a long way to go before we understand it.

I'd hold off banking too heavily on anecdotal data. That's how everyone got all worked up about this reinfection story a few weeks ago.

With respect, the story of both governmental and private sector response to COVID has almost universally been not being worked up enough.

Surely the right response to that isn't to always be more worked up.

I think he means plan for the worst, hope for the best.

From what I can tell, the governor in my state (CA) took an appropriate level of actions at roughly the right time (after realizing that the federal government declined to be useful). We appear to be passing through the first big wave of deaths, and cautiously reopening slowly. It's unclear what additional actions would have changed things (in terms of reducing total # of deaths, or any suffering while sick).

Sure, but by getting yourself worked up you're not improving that situation any.

Have we looked closely for blood clotting problems and other odd symptoms with other respiratory system viruses? People get unexplained blood clots all the time. How do we know they weren't caused by a hidden viral infection?

I have a feeling that in 2120 people are going to look back at us as idiots for missing a lot of stuff that will seem obvious in retrospect.

Pretty sure they will have pictures of Florida beaches and the reopen protests beside pictures of the SF Spanish Flu reopening and think we didn’t learn a thing in 100 years.

I've seen suggestions that a lot of these strange problems happen sporadically with other viruses like the flu too, and it's just more newsworthy when it happens with Covid-19.

This.

All the weirdness and horrors of "normal" diseases are now in the spotlight due to media attention on covid-19.

Those problems are common with regular flu.

I had lots of complications the last year with a common flu. My joints and some internal organs became inflamed because of the immune response and I could not move and was very painful.

This year I got covid early from meeting a person coming from Shanghai. I thought it was a weak flu.

Now I give positive in antibodies test.

A lot of the reports you're citing are just press-release-science being turned into breathless headlines.

Reinfection can occur with most viruses when a person is exposed too soon after the primary immune response. It takes a while for someone to develop full immunity after recovery. This happened with H1N1 for patients back in 2008.

https://www.virology.ws/2009/12/28/reinfection-with-2009-inf...

Are we talking 2 weeks, a month or 3 months, 6 months+?

Does viral load also matter? I would imagine that getting hit with a high number of viruses shortly after recovery could cause some issues but I'm just an observer in all of this.

Seems like this would make serology tests a lot more useful. I would really like to know if I've had it so I can know how at-risk I am (and consequently the risk I pose to others).

> In other words, when you recover from covid-19, you are immune to it. In other words, covid-19 is just like every other virus, in this respect.

"Every other virus" doesn't behave the same in this regard. The viruses that cause colds, many of which are also coronaviruses, are pretty adept at hitting people throughout their life.

Hopefully it's not an issue here, but it's completely unsurprising that people would want to actually research it instead of just declaring all viruses are the same.

The only fools here are the people whose impatience leads them to declare absolutes ahead of times instead of taking preventive measures while the research plays out.

https://www.npr.org/sections/goatsandsoda/2020/03/20/8190384...

> Researchers do know that reinfection is an issue with the four seasonal coronaviruses that cause about 10 to 30% of common colds.

Yes. It's suspected that immunity is very short lived.

> This study provides evidence that re-infections with the same endemic coronavirus are not atypical in a time window shorter than 1 year and that the genetic basis of innate immune response maybe a greater determinant of infection severity than immune memory acquired after a previous infection.

http://www.columbia.edu/%7Ejls106/galanti_shaman_ms_supp.pdf

Even if you recover, there's not a lot of evidence now as to what the duration of immunity will be. With this spreading through the world at different paces, it means that, as commonly predicted, we will see continuous re-emergence as we do with other cold viruses and influenza.

Recovered patients from SARS-1 had long-term antibodies in good concentrations until about 3 years after the infection. We can expect about the same since both coronaviruses are so similar.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/

Maybe we will end up putting this new vaccine research to good use and see if we can knock out some of the other coronaviruses. I'd love a combo vaccine that immunized against a bunch of common cold variants.

"it's completely unsurprising that people would want to actually research it instead of just declaring all viruses are the same. The only fools here are the people whose impatience leads them to declare absolutes ahead of times instead of taking preventive measures while the research plays out."

This hypothesis ("SARS-Cov19 does not confer immunity") falls roughly under the same category as intelligent design: the claim is so exceptional that it's a priori unlikely to be found true, and laypeople are taking normal scientist hedge-speak and exaggerating the meaning in their heads (e.g. "evolution is just a theory").

There was never really any question to anyone with any serious scientific training that humans would develop some degree of immunity to this virus. That's why people were saying it was more likely to be assay error from the start. The only open question here is how long that immunity might last. Even then, it's fairly clear that short-term (~months to a year) immunity is highly likely.

(Note: I have a doctorate in biochemistry with a specialty in molecular biology, and I've studied virology and immunology. I'm not just tossing off uninformed opinions.)

> this falls roughly under the same category as intelligent design debate: the claim is so exceptional that it's a priori unlikely to be found true

No. As the person you're responding to pointed out: "The viruses that cause colds, many of which are also coronaviruses, are pretty adept at hitting people throughout their life."

"No. As the person you're responding to pointed out: "The viruses that cause colds, many of which are also coronaviruses, are pretty adept at hitting people throughout their life.""

Yes. I'm talking about the question of immunity, not whether or not it's possible to get re-infected by new strains of the same virus, or whether or not immunity fades over time. It would be unlikely that this virus didn't confer at least short-term immunity to the host.

The viruses that cause colds primarily re-infect because they mutate at a very high rate. We aren't seeing that with this particular virus.

One of the currently popular mutants of the virus has a mutation in the proof-reading exonuclease that causes the virus to mutate much more often than the original strain.

https://translational-medicine.biomedcentral.com/articles/10...

"that causes the virus to mutate much more often than the original strain."

This is not claimed anywhere in the paper you linked to. They show a non-synonymous mutation in RNA-dependent RNA polymerase, and hypothesized that it could impact drug resistance.

My bad, I was misremembering the paper, which mentions the exonuclease's role in fidelity. I meant RdRps. The conclusion was the same. Figure 4 shows quite clearly that the RdRp mutation is associated with further mutations.

> We found that viral strains with RdRp mutation have a median of 3 point mutations [range: 2–5], whereas viral strains with no RdRp mutation have a median of 1 mutation [range: 0–3] (p value < 0.001, Mann–Whitney test). The different distribution between the two groups relative to the number of mutations is statistically significant (Fig. 4).

Immunity != long-term immunity.

You can get temporary immunity that lasts for a year or so and still be able to get reinfected multiple times in your life.

And there are hundreds of strains and types of viruses that cause colds. Immunity to a rhinovirus serotype will not help with other serotypes of rhinovirus, let alone all the coronavirus strains and influenza viruses.

Hmmm, I think I am going to list to the other guy, who has a doctorate in viruses.

> This hypothesis ("SARS-Cov19 does not confer immunity") falls roughly under the same category as intelligent design: the claim is so exceptional that it's a priori unlikely to be found true, and laypeople are taking normal scientist hedge-speak and exaggerating the meaning in their heads (e.g. "evolution is just a theory").

So call the null hypothesis "there will be some level of immunity." But then you see some people testing positive again, and it's reasonable to want to know why. I didn't see people officials leaping to planning for zombie apocalypse "we're all gonna get it over and over forever" scenarios, I saw people saying we needed to dig deeper.

A lot of people in this discussion are refuting a straw man idea that everyone had decided "clearly you get no immunity at all".

> But then you see some people testing positive again, and it's reasonable to want to know why.

I have been following the statements of experts ever since this myth made headlines.

And despite what the headlines said, the opinions of experts has always been clear. That being that these "reinfections" were the result of dead virus material being detected.

So, no it is not reasonable to have ever believed this, if you had listened to the experts.

> The viruses that cause colds, many of which are also coronaviruses, are pretty adept at hitting people throughout their life.

Yes, but you're almost always immune for at least a year. By then, we should be getting close to a vaccine.

And when you do get one of those viruses again, it's significantly less severe the second time.

Note that the immunity is not permanent. The average immunity to the endemic coronaviruses that cause the common cold lasts about a year.

Could you provide a source? Happen to be studying this topic for a paper I'm writing

Sure: https://www.technologyreview.com/2020/04/27/1000569/how-long...

In the interpretation of the NYS serostudy most favorable to your argument (assume perfect specificity), with 21% actually infected in NYC proper, based on the death statistics and the population of NYC, C19 appears to be a full order of magnitude more lethal than any recent flu strain. That's more than "somewhat" more lethal.

Putting this into perspective: in roughly a single month, we've already doubled the 7-year average annual number of flu deaths.

Project those C19 stats out across the whole population, and assume (generously) herd immunity effects at 70% that halt the progression, and you're looking at mortality rate that swamps that of all wars, terrorist attacks, and natural disasters faced by the US for the last 50 years, right?

Put differently, unchecked and with that extrapolated fatality rate, we'd be looking at something like 53 years worth of flu deaths at the average annual flu death rate? (Again, I'm just averaging the last 7 years for which we have flu stats; they range between ~12k-45k.)

(Happy to have my math corrected).

This idea of putting 50 years of any war/ attacks etc is misguided and it’s a wrong use of statistics. A better approach would be to take into account other diseases as you have with its close relative the flu. Others on the list would be other types of diseases. Because all of those dwarfs numbers from wars etc.

Why is it "misguided and a wrong use of statistics"? It's true that the flu kills far more Americans than the last 50 years of war has. If a new disease emerged that was just the flu in a different form, and we retained the mortality rates both from the flu and that new disease, that alone would be extremely alarming: a new cause of death, displacing none of the other deaths, that exceeds most other causes!

Honestly, I think we don't do nearly enough comparisons between disease mortality and other causes of mortality. A "War On Cancer" would have done us far more good than the wars we declared in the 2000s would have.

Nixon signed a bill in 1972 that declared just such a "war on cancer". This war has not been won. A few cancers have been reduced, but cancer as a whole remains intractable. Most of the decline in cancer deaths over the past decades are due to fewer people smoking.

I'm not saying that wars on "terror" are a good thing. It's just that cancer is a very tough problem.

the more precise wording would be that you're comparing different time periods and then using that to extrapolate rationale. that's an error of statistical reasoning.

the more accurate exapolation would be relative to the first 4 months of every other studied emerging disease, considering the estimated errors of each of the important variables. you'd fit the various current studies on corona/covid, considering the high uncertainty as (large) estimated error, and providing a range of future outcomes with probabilities on them.

instead, you're asserting your worst possible scenario as the most likely outcome.

~~~~~~~~~~~~

now on the idea that we're entirely too blasé about preventable mortality in general, i agree. if we rigorously and intelligently attacked auto accidents, if we addressed cardiopulmonary diseases caused by pollution and poor habits, and if we regularly shut down the economy for the past decades because we want to reduce the hundreds of thousands of contagious disease fatalities every year and had the socioeconomic safety nets in place for that all along, then the current actions would seem more reasonable.

instead, the response is out of proportion with our own past actions because of panic and fear. it happened with 9/11, mass shootings, fukushima, and everything else. the herd is not good at reasoning about rare and novel mortality events.

Or traffic collisions. Not a disease, but I think your argument makes it enter the discussion.

"...and assume (generously) herd immunity effects at 70% that halt the progression..."

That's not generous, or not generous, it's just a ballpark guess based on the best (conflicting) data we have so far. You're also discounting the fact that with every individual to gain immunity, the transmission rate is reduced. You're also extrapolating from what may be the worst possible phase of this virus. As time passes we develop better treatments and medications, we have more necessary equipment where it needs to be, we have better early detection and so on.

"...you're looking at mortality rate that swamps that of all wars, terrorist attacks, and natural disaster"

Lots of things swamp those numbers. For example, the flu.

That the flu is a reasonable baseline was obvious enough that I included it in the comment you responded to. The comparison is not reassuring. And the notion that "every individual that gains immunity reduces transmission rate" is exactly what "herd immunity" captures.

Herd immunity occurs when enough members of a population are immune to make sustained transmission impossible. But the transmission rate declines with every immune member of a population, far before herd immunity occurs. Same logic, but a different phenomenon, and one most people seem to overlook.

You're trying to bring galactic brain thought to a rather mundane, simple, calculation. (Fine, 1993) Please don't try to be a contrarian when out of your field, you end up making 'not even wrong' statements

At peak flu season, is seasonal flu the leading cause of death week over week, month over month, ahead of heart disease and cancer?

I haven't looked it up, but 55,000 flu/pneumonia deaths a year is about 153 a day, compared to COVID-19 running near 2,000 a day:

https://public.flourish.studio/visualisation/1727839/

This visualization is from before the acknowledgement that COVID-19 deaths were only counting confirmed positive / presumed positives from the earlier set of CDC symptoms, not the 3x larger set of symptoms revised last week.

Also doesn't account for second order deaths such as those with other health problems not seeking treatment from an overloaded system, or providers in the system committing suicide from PTSD.

55k/yr is also much higher than the actual average number of flu fatalities per year, which is closer to 35k even if you include the preliminary stats from the last 2 years (which captures the particularly bad flu year we had in the '17-18 season).

On the other hand, you can't discount the fact that 20-60K Americans die of the flu each year after we developed a vaccine due to its propensity to mutate. The vaccine is only 10-60% effective depending on the year, while early signs are pointing to COVID not mutating in the same way so a single vaccine (or single infection) may be enough to protect you -- potentially for a very long time.

Taking into account the lack of all immunity to and lack of vaccine for COVID to date, and just how much more virulent COVID is (therefore front loading the disease burden) in the full course of time the flu is almost certainly going to take a much, much larger toll.

It's killed 600,000 people per year, each and every year you've been alive worldwide. So far, COVID is at 1/3 of a year's worth of flu deaths -- let alone a lifetimes -- and are approaching 25%+ of the population of some high profile cities infected. Once it gets to 70% or so, it's most likely going to burn itself out due to herd immunity.

Why are you moving the goalposts? We're discussing US mortality figures, and in the US we have good stats on this, and they average out to ~36k fatalities annually.

I'm not moving any goalposts, goalposts remain in tact. And I'm using the same source: both numbers come from the CDC. So for your reading pleasure:

"It's killed 20-60K people per year, each and every year you've been alive in the US. So far, COVID is at about a year's worth of a bad flu deaths in the US -- let alone a lifetimes -- and are approaching 25%+ of the population of some high profile cities infected. Once it gets to 70% or so, it's most likely going to burn itself out due to herd immunity."

It brought me great delight to watch you confidently declare _you_ are the one with a full nuanced and fair grasp of this situation.

You calculate herd immunity % from R0, and it's odd to decide 70% is not generous and ballpark guess because you think the data "conflicts" - there's no "conflicting" between values in a range, go ahead and cherry-pick the lowest R0 you've seen and find out what the herd immunity % required is based on that (higher than 70%)

Won't even touch you trying to pretend this is the same as the flu, plenty of other threads address that.

I've made it clear already, but just to reiterate, this is one of the worst comments I've seen on HN in a while.

>Putting this into perspective: in roughly a single month, we've already doubled the 7-year average annual number of flu deaths.

I am really surprised how often I have seen "it is just the flu" type rhetoric upvoted on HN. I thought this was an intelligent, technological, scientific, and logical community. I don't see how anyone can square the idea that it is just the flu with evidence like what you posted above. COVID-19 has already accumulated a higher death toll in the US than any flu in over 40 years (I'm sure it is longer, but that is as far back as I can find data on with a quick Google search). That is all with basically the entire country under stay at home orders. There would be hundreds of thousands if not millions of deaths if we treated this like the flu.

Also: even if it was "just the flu": another flu would be a catastrophe all its own! You can still die of the flu, even in the post-C19 (or F19) world!

Not necessarily. The flu mutates substantially and often, and new subtypes keep popping up making a consistently effective vaccine elusive (flu shots are 10-60% effective each year based on our ability to guess which strains will dominate). There's no meaningful evidence indicating the same is true for COVID yet, so once we've all had it -- or a vaccine -- it could be over just like that, never to be heard from again. Unlike the flu. In the full course of time the flu may well prove to be much more dangerous.

Time will tell. Not saying one way or the other just that the worst case you've illustrated is far from a foregone conclusion.

I never said that this is "just the flu". I put some thought into my comment, and it's provoked some discussion.

Let me provoke some more: I predict that, by the end of this year, the number of total deaths in people over 85 will be about the same as last year.

I'm using the fact that most deaths from this virus occur in people who are already ill from other conditions. Frail old people are much more vulnerable to succumbing to infections.

Last year, about 13.5% of people over age 85 in the USA died [1]. That high death rate means that, at some point in the year, 13.5% of those people fell very ill, and had only months to live. This year, without the pandemic, a similar proportion of people would be close to death. If they caught the virus that causes covid-19, their death would be hastened. However, they would have died anyway, this year.

I know it's callous to say "they would have died anyway," since death is a terrible thing. However, humans have a limited lifespan, for some mysterious reason, and at some point our bodies start to betray us: we develop heart disease or cancer, and our immune systems become less effective. It's as if our bodies are lowering their defenses, almost inviting death. Often, along comes a flu, to finish the job. This year's angel of death is a different respiratory virus, not influenza.

1. https://www.cdc.gov/nchs/products/databriefs/db355.htm

According to this admittedly outdated CDC page[1], the 85+ age group makes up 30% of COVID-19 deaths. Even if you are right about that group (which I think is feasible but unlikely), there is still a huge population of people who are dying who were not previously close to dying.

[1] - https://www.cdc.gov/nchs/nvss/vsrr/covid19/index.htm

That's not an entirely fair way to slice, since only 6% of deaths in any age group are folks without comorbidities. I'll dig up the reference, pretty sure it was NYC data. We'll have to wait for the dust to settle but I'm pretty sure we're looking at an upper bound worst-case of basically everything we've measured re COVID.

I'm at a loss for why anyone should care about the fact that younger people dying have "comorbidities". If asthma or hypertension have suddenly become a death sentence, that is a very big deal; virtually every American has families with one of the "qualifying" C19 comorbidities.

It's not a death sentence by any stretch, you're substantially overreacting.

CDC data puts the US flu fatality rate at 0.1% (up to 20-60,000 deaths for 45,000,000 annual infections ~= 0.1%) and serology studies are putting COVID at around 0.3% -- not adjusting for comorbidities. So it's worse than the flu overall, but massively skewed older so for young and especially young and healthy people it's not materially different than the flu. For kids, its better than the flu -- which kills both the young and the old.

And yeah, the flu kills seemingly young and healthy people, too, we just don't really talk about it.

For old folks, it's much worse. We need to keep them safe, but that doesn't mean we need to freak out about children catching it when they're gonna be just fine. [1] Remember 99.2% of the folks who died in Italy averaged 80.5 years old with an average of 3 comorbidities. Zero health professionals under the age of 49 died in Italy despite constant and repeated exposure. [2]

Not everyone is equally affected by COVID and for the overwhelming majority (99.7% of all people), it's by no means a death sentence.

I strongly suggest you read [2] for perspective. I know all the breathless screaming on television has colored your perspective on all this, and yeah, it's not great. However, allow data to be your guide. We're gonna be just fine.

[1] https://www.wsj.com/articles/consensus-is-emerging-that-chil...

[2] https://www.cebm.net/covid-19/global-covid-19-case-fatality-...

It is weird how you are insistent on focusing in on how comorbidities impact COVID patients but ignore the same comorbidity issues for flu patients. Also not all comorbidities are created equal. I can understand the original argument if everyone dying of COVID-19 had stage 4 lung cancer, but there are people dying with chronic conditions like asthma that traditionally have little impact on life expectancy.

Also the 0.3% number you are referencing is being questioned as other serology studies have shown it to be 2x-3x higher. The reality of the situation is that we don't know the exact fatality rate of COVID-19. What we do know is that it is at least a few times more deadly than the flu and potentially an order of magnitude more deadly. We also know that the coronavirus is much more infectious than the flu. Like previously mentioned, we have already passed the worst flu numbers even while most of us are under a stay at home order. It seems like no matter how you look at the data, the only way in which COVID-19 is not worse than the flu is how it impact the very young. COVID is more deadly in basically every other way. I honestly don't see what people gain from continuing to downplay this disease in relation to the flu.

> It is weird how you are insistent on focusing in on how comorbidities impact COVID patients but ignore the same comorbidity issues for flu patients.

That's fair, although age matters way, way more, so we can elide the bit for future re-readings.

> Also the 0.3% number you are referencing is being questioned as other serology studies have shown it to be 2x-3x higher. The reality of the situation is that we don't know the exact fatality rate of COVID-19. What we do know is that it is at least a few times more deadly than the flu and potentially an order of magnitude more deadly.

I'm not just referencing the Gangelt data, but also the Vo data, and the Santa Clara data (which is very much in question now). That was also approximately the IFR for the Diamond Princess (0.85%) but of course Diamond Princess skewed much older so likely that IFR represents an upper bound. There are precious few population studies for us to reference, but they're far more valuable for making public health decisions than the ratio of people who go into a hospital as compared to come out. That only defines the numerator, without defining the denominator.

I'm also basing it on the estimates during the pandemic that H1N1 had a CFR of 0.1-5.1% from country to country, and landed on an IFR of 0.02%, or one-fifth the lowest estimate. [1]

> What we do know is that it is at least a few times more deadly than the flu and potentially an order of magnitude more deadly.

Not for all demographics. It's demonstrably less fatal for children, which the flu does not spare, and approximately the same for folks under 49.

> Like previously mentioned, we have already passed the worst flu numbers even while most of us are under a stay at home order. It seems like no matter how you look at the data, the only way in which COVID-19 is not worse than the flu is how it impact the very young. COVID is more deadly in basically every other way.

There's reasons you shouldn't compare COVID's current numbers to an average flu season. One being that COVID's new so none of us have immunity. It's also more virulent. It's affecting a similar size population but just all at once instead of spread out, so it's impact is concentrated in time. That makes it not particularly meaningful to project out. Not to mention that flu number is after a vaccine and after a lifetime of exposures, so likely doesn't represent an apples to apples comparison. If the flu vaccine is 10-60% effective, you should probably multiply the number of expected flu cases by up to 2 - or more. Think of it more like the first time someone caught the flu.

Further, the flu changes regularly, and comes back at us repeatedly, and COVID may well not -- early indications are promising in that regard.

I'm not trying to downplay anything, I'm trying to synthesize the data we do know and not fall into the panic that is dominating the discourse. We shouldn't make big decisions while scared senseless, we should allow the data to dictate as much as possible.

Saying this disease is a "death sentence" for an asthmatic 20 year old is panic. It's just not that. 17% of hospitalizations involved asthmatics in the month of March [2] while 8% of the US population has asthma. So I guess your risk is doubled. From 0.3% to 0.6% without adjusting for age. That is not a death sentence.

[1] https://www.cebm.net/covid-19/global-covid-19-case-fatality-...

[2] https://www.cdc.gov/mmwr/volumes/69/wr/mm6915e3.htm#T1_down

I'm just letting you know this is where I drop out of this debate.

You are not being consistent in your arguments. You are criticizing me for not making an apples to apples comparison and in the same paragraph you are doing exactly that by talking about all the preventive measures that reduce flu deaths while ignoring that the country is currently shutdown to prevent COVID deaths.

You are cherry picking statistics to support your point while ignoring data that conflicts with it. For example the data coming out of New York suggests a higher fatality rate and the numbers you are using from the Diamond Princess are either out of date or flat wrong.

You are both putting words in my mouth and pretending I didn't say things that I did. No one here ever said "this disease is a "death sentence" for an asthmatic 20 year old". I already admitted that the only group that has less to fear from COVID than the flu is the very young, yet you are still bringing up that point when I am talking about overall fatality rates.

> You are not being consistent in your arguments. You are criticizing me for not making an apples to apples comparison and in the same paragraph you are doing exactly that by talking about all the preventive measures that reduce flu deaths while ignoring that the country is currently shutdown to prevent COVID deaths.

Apologies, what I was trying to say is that comparing COVID now to an average flu isn't an apples to apples comparison even if the numbers land where they are now, for all those reasons, some of which are non linear. This is including the ones you mention. The flu has a vaccine, and plenty of past exposures. COVID has the shut-down -- though it also has huge virulence and asymptomatic transmissions that appear to be ongoing.

> You are cherry picking statistics to support your point while ignoring data that conflicts with it. For example the data coming out of New York suggests a higher fatality rate and the numbers you are using from the Diamond Princess are either out of date or flat wrong.

Indeed the Diamond Princess number was out of date. I'm suggesting that there's a broad spectrum of CFR estimates (0.08% to 15%) and there's reasons neither is representative.

> You are both putting words in my mouth and pretending I didn't say things that I did. No one here ever said "this disease is a "death sentence" for an asthmatic 20 year old".

GP, who I realize now is not you said: "If asthma or hypertension have suddenly become a death sentence, that is a very big deal;..."

It'll be interesting to see where the dust settles.

Speaking as the person you thought you were replying to: "younger" as in "than 85+", the context of the thread. "20 years old" is something you made up to make your argument look more sound than it is.

The 20-ish demographic is actually the worst case with respect to asthma, representing a larger than average proportion of asthma-positive COVID hospitalizations because they don't really have many other co-morbidities and they're young. It's all in the link I provided. 20-ish is actually to your advantage, not mine. I'm not trying to "win" anything, just provide some perspective.

I will just say kudos to you for admitting when you were wrong. Many people would have just ignored my comment and never responded.

Hey I don't wanna be wrong, always happy to be learn I am so I can stop ;) if my goal were to scream into the aethter there's easier places.

If you thought programmers were 'scientific and logical' you'd be dead wrong. I used to think that too but after years of experience and seeing so many cargo cult, gut feeling, lazy opinions, bad optimizing just within programming itself, you realize that as a group we are quite prone to emotional argument, lack of discipline and general laziness with argument or research on a topic.

>I am really surprised how often I have seen "it is just the flu" type rhetoric upvoted on HN

This is a unfair way to respond to [alejo's] comment. The fact that you have responded in this way to this thoughtful response suggests to me that the problem may lie in the way you are reading, understanding, and internally labeling other people's views.

That's more than "somewhat" more lethal.

Er, yes.

Project those C19 stats out across the whole population, and assume (generously) herd immunity effects at 70% that halt the progression, and you're looking at (a) mortality rate that swamps that of all wars, terrorist attacks, and natural disasters faced by the US for the last 50 years, right?

Yes. "Flattening the curve" just means keeping the hospitalization rate below what the medical system can handle. The curve stays flat near the peak rate. See the curves at [1]. The Financial Times has been updating those daily since early March. Some countries show a decline, but other than China and South Korea, which did heavy testing and lockdown, most countries peak and decline a bit, then level out above 50% of peak.

That continues until "herd immunity", either via vaccine or exhaustion of uninfected people. That's somewhere around 70-80% for this.

The vaccine situation is looking up. At least two vaccines are already beginning clinical testing for effectiveness. One from Oxford, one from Germany.

[1] https://www.ft.com/coronavirus-latest

This has been Derek Lowe's shining moment; his vaccine coverage has been fantastic:

https://blogs.sciencemag.org/pipeline/archives/2020/04/23/a-...

It includes additional promising candidates.

As I understand it, and I'd be happy for expert correction: lockdown has additional benefits beyond curve flattening; it also accounts for decreased transmission, which can get us to a point where we can track and suppress outbreaks individually while opening up the economy. That's essentially what seems to have happened in South Korea.

The lockdowns appear to have also stopped transmission of most other infectious diseases. Notably, influenza.

Influenza has a lower R0 than SARS2, and it absolutely kills people. Worth destroying our economy over, all by itself? Ehhhh... I mean, we could have done this at any time, and we didn't, so no.

Nice side effect that translates directly to lives saved? Absolutely.

Does it offset other probable side effects, such as increased heart attack mortality from patients being unwilling to go to the hospital, or increased suicide risk from sudden business failures and unemployment?

No idea, like, none. Biostatisticians are going to be crunching 2020 for the rest of the decade.

The decision is not in reality between "destroying the economy" and "opening the economy up", because even in places that aren't doing strict lockdown, economies are cratering. Even if you opened everything up, people would still make their own decisions to participate or not in the economy, and right now, it looks like they're going to make the economically painful choice.

So then: if you're going to take on a massive economic hit just from altered consumer behavior, does it make sense to get the worst of both possible worlds by also relaxing regulatory constraints that are demonstrably saving lives?

You're drawing more out of that turn of phrase than I intended. Which makes sense under the circumstances, people are drawing lines in the sand and "open at all costs" is one of those lines.

It's not my stance. This is more narrowly-focused than that: we could end the flu season early, every year, by imposing lockdown from January 1st to February 15th.

But we don't, and this isn't the flu, it's a novel disease which kills many more people by even the most conservative estimate.

Still, as a side effect of the eminently rational (and economically painful) precautions which we've taken against it, ending the flu season a couple months early is a nice bonus.

One factor people often forget in the fatality equation is the attack rate, or how many people can be potentially be infected. For the flu, it is around 10% to 15% yearly. For C19, it could be >80% given that there is no natural immunity nor vaccines. Taken that into account, C19 could be at least 40x deadlier than the flul (Flu: 0.1% CFR 10% AR, C19: 1% CFR 40% AR). The 0.1% CFR for the flu is taken from the estimates of the 1957 and 1968 pandemics, which left 100K fatalities in the US. Estimates for the seasonal flu are lower than 0.1%.

There have also been cases where people looked like they've recovered, tested negative, and then became ill again after 2 weeks and tested positive again.

I always suspected those were mostly due to false negatives from PCR tests. Probably only a tiny minority of people had not enough immune response for them to become reinfected.

Given a large enough sample size, you're also going to get people who recover, test negative due to a false negative, then get influenza two weeks later, then test positive due to dead SARS-COV-2 RNA.

And various other edge case permutations like that.

Virtually all messaging I've seen has been "We lack evidence to say how immunity works" with a dose of "there's some initial evidence suggesting immunity" and "we aren't sure about how long it lasts".

It's interesting to read "it's extremely infectious" and "more lethal than influenza" followed by "that's all", not to mention the missing bit about not having a vaccine!

If we saw a massive outbreak of influenza things would be extremely different. We have treatments for influenza (tamiflu), we have vaccines, we have understanding, and a large portion of the population that is already immune.

The similarities are... they are both viruses. Not sure why anyone would compare the two except to try to explain how different they are.

I don't think we have any reliable evidence of post-recovery immunity at all. I wouldn't expect to have any until we've seen multiple cycles of this virus, and analyzed the data carefully. Press-release-science during an emergency is close to worthless.

If you don't have any post-recovery immunity, then how do you ever recover to begin with?

immunity prevents you from being infected, not from eliminating the virus. People who are cured of AIDS by eliminating HIV aren't then immune.

HIV is a bit of a special case to begin with, since it's attacking the very immune system that would try to kill it. But is anyone clearing the virus on their own? I thought it required extensive retroviral therapy, and even then it isn't actually cleared?

Admittedly, I don't really keep up on the status of HIV, maybe something has changed.

A very small number of people have natural immunity. https://en.wikipedia.org/wiki/Innate_resistance_to_HIV

I am not sure if anybody gets infected, then clears the virus on their own.

Sigh. I was waiting for the "Govts have overreacted" message. This is a ridiculous criticism to have to the response to this pandemic. We NEED to overreact so we don't underreact.

> In other words, when you recover from covid-19, you are immune to it. In other words, covid-19 is just like every other virus, in this respect.

That’s not how HSV works. That’s not how hepatitis works.

“Just like other coronaviruses”

There you go

Even that's not true. 15-30% of the viruses that are attributed to the common cold are coronaviruses, and it's pretty clear that the common cold does not behave in the way OP described.

Do you know about genetic drift/shift/different strains?

Moreover, recent literature continues to confirm that you have protective immunity after recovering from covid like any other coronavirus. This is the basis for convalescent plasma therapy

Yes, but you’re drifting from the original point I was arguing against: “all viruses act exactly like the flu, therefore governments overreacted by not immediately assuming it was exactly like the flu” - which has a false premise.

No, it’s you who’s drifting away from “Just like other coronaviruses”

You don’t get re-infected by HSV or chronic hepatitis; you don’t recover in the first place. In the first case the virus hides from the immune system, in the second it never properly overcomes the infection.

in the article it didn't mention whether when you recover from covid-19, you are immune to it.

> In other words ..

What you write is disconnected from the article, immunity was discussed more deeply elsewhere on HN already.

>In other words, when you recover from covid-19, you are immune to it.

Probably not.

It seems [1] that in humans and animals, there's no long-term immunity arising from infection.

[1] https://www.quantamagazine.org/what-can-other-coronaviruses-...

> In other words, when you recover from covid-19, you are immune to it.

At least for some time.

> In other words, covid-19 is just like every other virus, in this respect.

Other coronaviruses don't mutate, yet reinfect lots of people and cause some common cold roughly every two years.

I think we can expect roughly the same from covid19. Peak every two years until we have a vaccine. Then annual covid19 vaccine shot to refresh the immunity.

And why dead fragments can't join again to make full blown virus? Sure it seems theoretically possible, given enough number of patients - sooner or later, new virus will rise up like phoenix from ashes.

Viruses don't work that way.

Even if they did, it's not the point -- the presumption is that the immune system would handle them like it treated live viruses, with antibodies and an immune response. The point is that this isn't a second infection, it's dead fallout from the first one, and the patent is likely immune against reinfection.

Not always immune system can recognize fragment of a virus as threat even if it was battling the very same virus before.

it's not even that viruses don't work that way, entropy doesn't work that way.

You mean you don't assemble Lego models by putting all the pieces in a box and vigorously shaking it?

I have an infinite team of monkeys working on it...

That is what my Boltzmann brain just told me

> why dead fragments can't join again to make full blown virus?

Is a good question.

Around 220 species of viruses are known to be able to infect humans. Another 8 at least can affect dogs, but not humans. Lets say that 50 more viruses are exclusive from each one of dogs, cats, cattle, pigs, poultry and fishes and most main crops

Those species are studied. Less imagine that this list makes a total of 5000 viruses relatively well studied.

Well. In a conservative estimate, only Mammals could host more than 300,000 species of virus still unknown to science. There are, probably, several millions of virus still unknown only among arthropods.

Lets say that "1%" of the viruses don't work that way, and we don't know anything about the regenerating DNA capacities of the remaining "99%", but we can assume that probably will not happen. Probably. Viruses stop being functional when devoid of its capsides.

But... I wouldn't bet against viroids, in this sense. Fortunately, we aren't plants.

that's a noble attempt, but your argument boils down to "we don't know what we don't know" and "anything can happen", and that's true as far as that goes, but it's unhelpful in answering why viruses can't spontaneously reform from fragments. basic biochemistry and thermodynamics provide foundational knowledge in answering that question, not epistemology.

if you could run your argument through that foundational knowledge and form a coherent theory for how virii might spontaneously reform, we'd all be open to it.

Thermodynamic laws are of limited use in biology and notoriously useless to describe life being's behaviour. Third law in particular is useless here. You can't put both concepts of life and zero absolute in the same room. They are mutually exclusive. Either you have one, or the other, or none of them.

Claiming thermodynamics here is a false argument. Viruses can pass over thermodynamic laws all the time. They live in a bigger system that provides an unlimited source of materials, metabolism, energy and constant temperatures and where events like frost, ebullition or spontaneous combustion are just banned. The host pays the thermodynamic bills for they

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