[HN Gopher] A majority of uninfected adults show pre-existing an...
___________________________________________________________________
A majority of uninfected adults show pre-existing antibodies
against SARS-CoV-2
Author : nradov
Score : 150 points
Date : 2021-04-06 15:39 UTC (7 hours ago)
(HTM) web link (insight.jci.org)
(TXT) w3m dump (insight.jci.org)
| HarryHirsch wrote:
| Wait, you'd think that the four human coronaviruses that
| supposedly confer partial immunity against COVID-19 are endemic
| all over the world. If that's the case, why is Brazil doing so
| badly?
| mrfusion wrote:
| Is a lot of that perception coming from how the media reports
| it?
| cassianoleal wrote:
| The fact that in many states there are people dying for lack
| of hospital beds is not "perception coming from how the media
| reports it".
|
| I'm Brazilian born and raised, and even though have been out
| for about 7 years most of my friends and family are still
| there.
|
| The fact that pretty much everybody I know over there knows
| at least a handful of people who have died of COVID-19 and
| hell knows how many that have had it is not "how the media
| reports it".
|
| The struggle is real, the situation is pretty dire over
| there.
| 74d-fe6-2c6 wrote:
| Is it doing worse than before Corona? Or maybe it's just that
| media is now focusing on how bad the medical situation is?
| caiomassan wrote:
| You have to take into consideration a lot when thinking about
| Brazil. - the midia and the president are of two different
| gangs - data gathering in Brazil is a joke, the true numbers
| can be double the ones reported for more or less.
| outworlder wrote:
| Easily double. Probably way more than that. I guess the only
| way to know is from excess deaths statistics. Even that is
| confounded by the collapse of the health care system.
| cperciva wrote:
| Coronaviruses are strongly affected by climate -- that's why we
| have "cold season". Maybe the endemic coronaviruses aren't
| endemic in Brazil's warm and humid climate?
| maxerickson wrote:
| The paper addresses that question briefly:
|
| _It is unclear whether this antibody reactivity may confer
| clinical benefits, for instance, modulating the severity of a
| SARS-CoV-2 infection._
|
| I think quantifying any protective effect is gonna be pretty
| difficult.
| Animats wrote:
| Right. What this seems to be saying is that, for one tiny
| area of Vancover, BC, 90% of the people tested with a very
| sensitive antibody test showed that their immune system had
| encountered some relevant coronavirus and had reacted to it.
| Is that right?
|
| The trouble is that the article has a clickbait title: "A
| majority of uninfected adults show pre-existing antibody
| reactivity against SARS-CoV-2". Which may get translated into
| "We already have herd immunity" by some television pundit
| shortly.
| SpicyLemonZest wrote:
| Is it clickbait? It's a journal article, and as far as I
| can tell "antibody reactivity" is the correct technical
| term for what they're describing. Certainly some pundits
| will misinterpret it, but I don't think we can expect
| researchers to shape everything they write to avoid PR
| misunderstandings.
| throwawayfrauds wrote:
| I'd say that everything about this article is the opposite
| of clickbait. It's not buzzfeed, it's a science journal.
| loveistheanswer wrote:
| >you'd think that the four human coronaviruses that supposedly
| confer partial immunity against COVID-19 are endemic all over
| the world.
|
| What data is there that indicates this is the case?
| curiousgeorgio wrote:
| Question: Could a COVID-19 vaccine (or any vaccine for that
| matter) have contagious immunity? In other words, is it possible
| (at present or in future vaccines) for the safe variation of the
| virus (or whatever the delivery agent) to be passed from person
| to person?
|
| I understand that without symptoms like coughing or sneezing, the
| vector for spreading would be relatively limited, but I have to
| imagine it's still possible (even commonplace) for healthy
| individuals to effectively spread bacteria/viruses (even harmless
| ones).
|
| If it is possible, what are the chances of that happening
| unintentionally? Would it be ethical to engineer a vaccine to
| intentionally do that?
|
| I'm not trying to imply that's what's happening now - but I am
| curious.
| dragonwriter wrote:
| > Could a COVID-19 vaccine (or any vaccine for that matter)
| have contagious immunity? In other words, is it possible (at
| present or in future vaccines) for the safe variation of the
| virus (or whatever the delivery agent) to be passed from person
| to person?
|
| If a vaccine used a virus that was both live and contagious but
| somehow safe, its not impossible; of course, there'd also be a
| risk of it mutating to become unsafe.
|
| The actual vaccines for protection against COVID-19 that I know
| of don't use a delivery mechanism where that is possible;
| that's certainly not something, e.g., a mRNA vaccine could do.
| programmarchy wrote:
| To summarize it's due to cross-reactive immunity resulting from
| previous coronavirus (but not CoV-2) infections. Up to 90% of
| uninfected adults have these antibodies already.
|
| Could this explain why many people have mild cases but some have
| severe cases? I'd be curious to find out how effective the cross-
| reactive antibodies are compared to ones produced by a vaccine.
| sdfhbdf wrote:
| > In total, 276 healthy adults were recruited for this cohort
| between May 17th and June 19th 2020. (...) The majority (n = 196;
| 71%) were health care workers
|
| This number seems low. I think the title is poorly worded, to me
| it concludes more of that healthcare workers in Canada developed
| antibodies before being diagnosed with COVID-19
| SketchySeaBeast wrote:
| I'm unsure to the conclusions we can draw as Vancouver is
| currently at the start of a third wave. I don't believe BC is
| performing asymptomatic testing so these will be people who have
| enough symptoms to get tested so it's clearly not enough
| protection to keep from showing those symptoms.
| maxerickson wrote:
| The study took their samples in May and June of 2020.
| SketchySeaBeast wrote:
| Oh sorry, I thought they were doing A/B and the second was
| later for some reason. Nevermind.
| WalterBright wrote:
| I suspect I had a very mild case of covid a year ago, but I was
| never tested. Nevertheless, I have a vaccination appointment for
| Thursday.
| tucosan wrote:
| It would be nice if HN would be a place that is free of Corona
| related debate. Especially, since most people here are not
| qualified to draw the correct conclusions from studies such as
| this.
| loveistheanswer wrote:
| Locking down scientific studies from the greater scientific
| community and the general population is a terrible and anti-
| scientific idea
| ismyrnow wrote:
| The people in this community are more qualified than most
| people in my social circles for debating this topic, and tend
| to be less motivated toward bias. People here tend to be better
| at referencing source material, facts, and statistics that
| support their thoughts.
|
| Although I don't usually seek out this topic in this community,
| I find these discussions here helpful from time to time.
| lamontcg wrote:
| > But here's the key part: "cross-react" does not mean
| "neutralize" and it does not mean "provide protection from".
| These antibodies may or may not have been neutralizing against
| the other coronaviruses, but they don't seem to have any such
| effect on the current one. And in keeping with that, having such
| cross-reactive antibodies seems to provide no protection against
| catching SARS-Cov2 or against being hospitalized with it if you
| do. There's no difference in the infection/hospitalization rates
| of the people who had cross-reactive coronavirus serum antibodies
| ready to go versus those who didn't. They're basically useless.
|
| > Now, you can still make an argument that the T cell component
| of immunity might provide some protection after a previous
| coronavirus infection. The current study didn't address this
| directly, but after these results, it's at least less likely that
| that's happening. The authors make a note of this, and also note
| that pre-existing mucosal antibodies might exert a protective
| effect (which this study didn't examine, either). But prior
| circulating human coronavirus antibodies, even ones that can bind
| to the current one - those it looks like we can rule out. Which
| is too bad.
|
| From:
| https://blogs.sciencemag.org/pipeline/archives/2021/02/10/do...
|
| The title study here is nothing new, we know there's cross
| reactive antibodies to other coronaviruses, they're not
| neutralizing, the hospitalization/death rates are the same so
| they don't confer any protection.
|
| Nobody had any pre-existing immunity to this virus before it
| erupted last year (and no, the virus or variants of it were not
| traveling the globe months or years earlier).
| vkou wrote:
| Studies keep saying this. People keep pointing to these studies,
| and demanding policy changes. But I've yet to see a study that
| makes any claims about:
|
| 1. What percentage of these people can catch COVID.
|
| 2. How likely they are to infect someone else if they do.
|
| For some reason, communities around the world keep getting
| second, third, fourth, and fifth waves of infections, _and viral
| variants keep evolving_ , despite the proliferations of studies
| like this.
|
| It's like measuring the level of humidity at ground level, and
| using that to conclude that it's raining. Yes, there's a
| correlation. No, that's not a reliable way to measure rainfall. A
| reliable way to measure rainfall is putting a bucket out.
| reedjosh wrote:
| Only somewhat related. What is the general thought on
| https://www.pandata.org ?
| mensetmanusman wrote:
| Hospitalizations will determine how truly close we are to what is
| 'effective heard immunity', Since we have no easy way of
| measuring at scale t-cell body immunity.
| frosted-flakes wrote:
| You can still get the disease, but not badly enough that you
| need to be hospitalized, especially if you are younger (old
| people got the vaccine first). But I think it's probably still
| an OK indicator of herd immunity.
| TameAntelope wrote:
| The "younger people are safe" idea is being challenged by
| these new variants. Additionally, discovering you're in an
| at-risk group by getting COVID is a pretty terrible outcome.
| risaacs99 wrote:
| What's been disappointing to me throughout this experience
| is the fact that a large percentage of people don't seem to
| understand contagion.
|
| The idea that a young person is safe is convenient for
| young people, but irrelevant. We never seemed to
| communicate to a segment of the population that we are
| trying to keep them from spreading it, as well as keeping
| them from catching it.
| kdmytro wrote:
| I think that this is communicated clearly enough. People
| will do what they want to do. For example, you can't get
| clearer than printing pictures of cigarettes-affected
| lungs with warnings on cigarette packs. Yet certain
| people keep smoking.
| anoncake wrote:
| If only we had been already exposed to the old variants...
| JulianMorrison wrote:
| Also younger people get Long Covid at _higher_ rates.
| timr wrote:
| > Also younger people get Long Covid at higher rates.
|
| We do not have a _definition_ for "long covid", let
| alone enough information to make such a claim.
|
| At best, this is blatant speculation, at worst, it's
| completely false. The best data for long-term sequelae of
| Covid indicate that it correlates with disease severity,
| which itself correlates (strongly) with age.
| subsubzero wrote:
| Agree, the media is really putting this "long covid" fear
| into younger people to just scare them to not congregate
| and spread the virus. Long covid can be substituted with
| long pneumonia, long flu etc. I had long flu back in
| early 2018, was extremely sick for 3-4 weeks, and went to
| the Dr. 12 times in 2 months, after almost 3 months was
| back to normal somewhat, still had cough and fatigue
| which finally went away after the 3rd month. Very scary
| times.
| timr wrote:
| I try to stay agnostic on the question, and simply
| counter obviously irresponsible speculation with facts
| and data.
|
| That said, the news media has been shameless about
| misinterpreting data consistently in order to promote
| fear. It's a real problem.
| linuxftw wrote:
| Need to cite data about 'young people' and variants. I've
| only seen speculative news reports, not hard data.
| sgt101 wrote:
| Tinfoil hat theory : the SARS-1 outbreak was bigger than
| documented in east asia and possibly there was an escaped variant
| with mild symptoms that circulated undetected for some time
| (testing was not so good 20 years ago). 20 years later places
| like Tiawan, Veitnam and South Korea have a chunk of their
| population with an immunity - a little like the immunity to Swine
| Flu conferred by Spanish Flu.
| myself248 wrote:
| I don't think that's tinfoil hat territory, it seems entirely
| plausible and not sinister at all.
|
| And super intriguing!
| maxerickson wrote:
| It would be odd for the milder variant to have a significant
| protective effect at that scale and not have spread further.
| sgt101 wrote:
| I agree - a bit odd, but not totally implausible. Chains of
| transmission do break for odd reasons.
| blackbear_ wrote:
| I am not sure how to reconcile this with the fact that there has
| been a global pandemic for the past year or so. Perhaps I am
| missing something obvious. Can anybody explain?
| maxerickson wrote:
| They didn't study whether the reactive antibodies were
| protective, just whether they were there.
|
| The thing the study establishes is that most adults have
| antibodies that will react to some parts of the pandemic virus.
| And then that's it. They didn't establish whether it was
| protective or not or anything like that.
| AnimalMuppet wrote:
| We had a global pandemic. In that pandemic, a _lot_ of people
| got exposed to Covid - exposed enough that they developed
| antibodies.
| Metacelsus wrote:
| Antibodies are only produced if a pathogen replicates enough
| to trigger the immune system. So mere "exposure" doesn't do
| it; actual infection does.
| mensetmanusman wrote:
| In principle the absolute number of virions matters.
|
| If you are exposed to 1000 versus 100,000, does one lead to
| an infection while the other indices some exposure
| response?
| lolc wrote:
| I would assume that most people have some sensitivity because
| they've been exposed to coronaviruses before. However this is
| not enough to quickly raise an immune response when the new
| variant shows up.
| ArkanExplorer wrote:
| The world gets hit with various 'Asian' superflus roughly once
| a decade:
|
| https://swprs.org/wp-content/uploads/2020/10/sweden-monthly-...
|
| This is just the first one that has hit at a time when it was
| politically and technically possible to shut down whole
| societies in fear of them.
| hire_charts wrote:
| It doesn't need to be a global/political conspiracy for
| people to be more sensitive to a large amount of people dying
| after almost 20 years of significantly lower death rates.
|
| Edit: Also, looking at overall deaths per million is not
| anything like comparing actual mortality rates of those
| infected. The baseline mortality in 1918 was already way
| higher and the pandemic amplified that, despite actually
| being less deadly than COVID-19 at an individual level. So
| I'd argue that the response to this pandemic was more than
| merited and was appropriate to the nature of the virus
| itself. It was not just another "asian flu."
| ArkanExplorer wrote:
| Deaths in Sweden are only 6% higher in 2020 than in 2018:
|
| https://www.statista.com/statistics/525353/sweden-number-
| of-...
|
| It would seem unlikely that the population would notice a
| 6% increase against the base annual death rate. We
| previously tolerated hospital overcrowding and death spikes
| from influenza waves.
|
| Most other countries around the world are showing a 4-6%
| increase. There seems to be a correlation to severity of
| lockdown and increased number of deaths, presumably due to
| factors like interruptions to regular medical treatments,
| and individual health deteriorating during lockdown.
| randomopining wrote:
| How do you factor in the projection of infections/deaths
| without any enforced lockdowns?
|
| Aka everybody gets it very fast and in a short time
| period, hospitals are easily overwhelmed and lead to even
| more deaths.
| loveistheanswer wrote:
| An alternate scenario could also be the most at risk
| populations (elderly, obese, etc.) lockdown, while the
| young, healthy, low risk populations gain quick herd
| immunity
| hire_charts wrote:
| See my edit above. Looking at a country's overall death
| rates is not how you should compare virulence.
| [deleted]
| andred14 wrote:
| How about start with proving that it even exists? The word of
| "experts" which have lied to us recently is no longer enough.
|
| Show us the proof I'm waiting...
| qbasic_forever wrote:
| Is this study really just telling us that 90% of adults have had
| a cold in the recent past?
|
| edit: Not implying SAR COV-2 is "a cold". I'm implying it's a
| coronavirus also like the common cold, hence an antibody study
| would have to be careful to select for the right one.
| whiddershins wrote:
| Can the common cold also be a rhinovirus?
| nradov wrote:
| Yes most common colds are caused by rhinoviruses or
| coronaviruses.
| second--shift wrote:
| yes, the "common cold" can be carried by rhinoviruses,
| coronaviruses, influenza viruses (maybe a mild case of 'flu'
| mistaken as a cold), and adenoviruses.
|
| this list is not comprehensive.
| Leherenn wrote:
| I've never really understood the link between "being cold"
| and catching the "cold". I assume it's because your immune
| system is somehow slower when you're cold, but the
| correlation seems pretty strong based on what I have
| observed. Other people and I very rarely catch a cold
| without being cold, and after being cold it's common to
| catch a cold. Are there *viruses floating (?) around
| constantly, and your body is severely less effective at
| fighting them off when cold? Is it just
| confirmation/survivorship bias?
|
| From what I can find online, there's a correlation, but
| it's pretty light on details about how strong it is.
| core-questions wrote:
| In the sense that people with rhinovirus symptoms usually say
| "I have a cold", yes.
|
| It seems it's best to think of "cold" and "flu" as totally
| informal terms with a wide range of possible meanings. I've
| had Actual Real Influenza twice and both times it knocked me
| on my ass for a week, lost weight, etc. yet I hear people
| saying "I have the flu" when they have mild symptoms and only
| miss a single day of work. Hard to take such a wide range
| medically seriously.
| foobarbaz33 wrote:
| > I hear people saying "I have the flu" when they have mild
| symptoms and only miss a single day of work.
|
| They could have had influezna with mild symptoms. Two
| different people can have the same influenza virus enter
| their body and experience different effects. Anywhere from
| no symptoms at all to death.
| theknocker wrote:
| I think it's funny that your edit is necessary.
| citilife wrote:
| It means their body responds to the virus, we aren't
| necessarily clear on why. Supposedly, this could be because
| they came in contact with SAR COV-2 OR some other virus which
| enabled the response.
|
| In this case, 77% of participants were in the medical
| profession and were evaluated between May and June 2020. I
| suspect they came in contact with SAR COV-2 and didn't even
| realize it (body fought it off).
|
| What this study is really suggesting is that your body either
| (a) has an immune response from previous contact (likely due to
| similarity with regular corona viruses) or (b) lots of people
| show no symptoms (we know this) and that they obtain an immune
| response from it.
|
| In either case, the SAR COV-2 is likely far-less dangerous in
| the sense that more people have it and there are less deaths
| per infection OR many of us have a natural immune response
| (more than previously suspected).
| maxerickson wrote:
| The conclusion the study authors came to is different than
| yours:
|
| _It is unclear whether this antibody reactivity may confer
| clinical benefits, for instance, modulating the severity of a
| SARS-CoV-2 infection._
| IgorPartola wrote:
| Well, we do know how dangerous this virus is. This new data
| doesn't tell us anything new because mortality rate is
| mortality rate and that's that. What this data might do is
| help point to what further research to conduct to try to
| figure out why some people have such strong reactions to
| COVID while others have few or no symptoms at all.
| nostromo wrote:
| > mortality rate is mortality rate and that's that
|
| Not really. Mortality rate is number of deaths / number of
| infections.
|
| We roughly know the total number of deaths. We have no idea
| what the total number of infections has been.
| nradov wrote:
| We can estimate the total number of infections through
| seroprevalence studies. The latest research shows a
| global infection fatality rate of about 0.15%, although
| there has been a wide variance between countries.
|
| https://onlinelibrary.wiley.com/doi/10.1111/eci.13554
| Townley wrote:
| Mortality rate is the ratio of deaths to individuals in a
| specific population.
|
| So there's the mortality rate for the overall population
| (what GP is referencing) vs mortality rate among people
| who've had COVID (what I believe you're referencing).
| Both are valid and useful in different circumstances:
| "How likely am I to die if I get COVID" changes as we
| discover a glut of asymptomatic cases, but "What % of the
| population will die of this disease?" stays the same
|
| Ref: https://www.merriam-
| webster.com/dictionary/mortality%20rate
| setr wrote:
| > "What % of the population will die of this disease?"
| stays the same
|
| That doesn't sound right -- you can't know the population
| death rate definitely without knowing the infection rate;
|
| If no one gets the disease in your sample population of
| 100, your death rate says 0. If 1 person is infected and
| 1 dies, your population death rate says 1%. If 80 are
| infected, and 10 dies, your population death says 10%.
|
| The "correct" number should be stable, but the population
| death rate should be changing as the disease spreads,
| approaching the correct number (but this is also true of
| liklihood of dying to COVID)
|
| Your population death rate would only be static if your
| sample population is 100% infected, which is the same as
| "How likely am I to die if I get COVID"
| IgorPartola wrote:
| You are getting a bit carried away. You aren't wrong, the
| number of people who already got sick and either
| recovered or died affects future infection rates. So do
| other things. But I'll use the example I used in another
| comment here: if you have 7.5 billion people in the
| world, and a rare disease that requires surgery where 100
| people per year get sick, and all 100 undergo the
| surgery, and 15 of them die due to post surgery
| infections, is the mortality rate of the surgery 15/100
| or 15/7.5 billion? If the latter, why?
|
| As another example: lots of people have the tuberculosis
| infection which lies dormant in their lungs. TB infection
| is distinct from TB disease which is where you get
| symptoms. The former is only dangerous in that it can
| develop into the latter. The latter can kill you. How
| should you look at these numbers? Is it worthwhile to
| drop the number of people with TB disease and just divide
| deaths by TB infections or is it more informative to
| derive mortality as deaths / TB diseases while also using
| TB infections and the conversion rate from those to TB
| disease to calculate risk and transmissibility? I argue
| the latter is much more relevant to decision making.
| playingchanges wrote:
| Keep in mind that the death rate still has to exist in a
| given time frame so only can only be extrapolated
| backwards and has to be recalculated annually.
|
| Strikes me as similar to those who predict x% returns on
| their s&p index funds based on past stock market
| performance.
|
| The future is always unknown.
| IgorPartola wrote:
| I don't think you can directly compare disease to the
| stock market. The stock market is a level 2 chaos system:
| predictions about it are direct inputs into the system
| affecting outcomes. Disease is generally much closer to
| level 1: it is random but unaffected by predictions.
| COVID is possibly mildly affected by predictions in that
| people might make travel plans based on predictions but I
| don't think the majority of people are acting in ways
| that seriously change their transmission risk based on
| predictions.
| [deleted]
| lixtra wrote:
| Most likely everyone in this thread wanted to talk about
| _case fatality rate_.
|
| https://www.merriam-
| webster.com/dictionary/case%20fatality%2...
| rhacker wrote:
| Mortality rate may be unknown. But we know it's killed at
| least a half million in the US alone, 3 million
| worldwide. There are also deaths not associated with
| Covid 19 but caused by it (they didn't get a test before
| or after death). That's still the highest rate of death
| we've seen since the last pandemic (spanish flu) caused
| in a single season by a virus. So yes it is dangerous.
| IgorPartola wrote:
| Thanks for putting that so succinctly.
| IgorPartola wrote:
| For practical purposes, do you want to count these
| symptom-free infections in that calculation? Knowing
| this, would you want to do anything differently in how we
| handle this pandemic? I don't see how this changes much
| at all about our present situation.
| mod wrote:
| What are you saying?
|
| We should continue to make decisions based on the pretend
| mortality rate and ignore the true one?
|
| Of course we "want to know it."
| IgorPartola wrote:
| I am not against knowledge in any way. More research will
| only help. What I am saying is that in the people who get
| sick, the mortality rate is 1-3%. This data does not tell
| us whether that generalizes to everyone or not because
| merely having these antibodies does not guarantee that
| you actually won't get deathly ill. It could be
| interpreted that you have full immunity or it could be
| interpreted that you have a weak immunity to COVID. More
| research is necessary.
|
| However the "pretend mortality rate" you refer to is not
| a thing. It is 1-3% in people who test positive, which
| correlates pretty strongly with people who have the
| disease. Think about it this way: the yearly flu in
| 2018-2019 had a mortality rate of 1.3-48.7% according to
| the CDC. The denominator in that was 61,000 or so cases.
| If you found out that 100,000 additional people were
| exposed to the flu but had no symptoms and by any
| definition had no flu illness would that change your
| outlook on whether the flu vaccine or hand washing is
| worth it?
|
| Or another example: there is surgery which has a
| mortality rate of 15% due to post surgery infection. Not
| everybody needs the surgery, only 100 people per year do.
| Does that mean the rate of mortality here is fake because
| the denominator should be 7.5 billion? Or should we only
| count the people who get the disease that necessitates
| the surgery?
| mod wrote:
| > If you found out that 100,000 additional people were
| exposed to the flu but had no symptoms and by any
| definition had no flu illness would that change your
| outlook on whether the flu vaccine or hand washing is
| worth it?
|
| Yes, of course my outlook would change. Not on the binary
| scale--i wouldn't suddenly think it's not worth it to
| wash hands-- but I would want to know when deciding on
| measures.
|
| The mortality rate is a specific figure, it's not
| whatever figure makes your reaction most appropriate.
|
| If some people get the virus and have no symptoms, that's
| an incredibly important piece of the puzzle when deciding
| how to proceed.
|
| Using your exaggerated examples, what if 99% of the
| population didn't suffer any adverse effects? Wouldn't
| you reevaluate the current response in light of that?
| IgorPartola wrote:
| > If some people get the virus and have no symptoms,
| that's an incredibly important piece of the puzzle when
| deciding how to proceed.
|
| This study does not tell you that these people had COVID.
| That's the point: we don't know what this means. All we
| know, is that we need to study this further.
|
| > The mortality rate is a specific figure, it's not
| whatever figure makes your reaction most appropriate.
|
| From Wikipedia: "Mortality rate, or death rate, is a
| measure of the number of deaths (in general, or due to a
| specific cause) in a particular population, scaled to the
| size of that population, per unit of time." What is the
| "particular population" here is in question. I argue that
| "people who had the SARS-CoV-2 disease" are the relevant
| population. That is, people who had symptoms or tested
| positive after an exposure. This study does not change
| this because it shows no source of the antibodies: if I
| inject my COVID-19 antibodies into your arm, it does not
| mean that you had the disease and therefore should not be
| counted in the mortality rate, does it? How those
| antibodies got there is a question yet to be answered but
| the possible answers range from "those people got a mild
| case and didn't notice" to "those people developed low
| level antibodies due to incidental contact with COVID-19"
| without getting the the illness. Their immune system is
| not trained well enough to fight off a higher viral
| load."
|
| > Using your exaggerated examples, what if 99% of the
| population didn't suffer any adverse effects? Wouldn't
| you reevaluate the current response in light of that?
|
| Yes and no. First, this study does not tell me anything
| regarding suffering adverse effects. But if a future
| study did, I think the 3 million people that have died so
| far would have wanted us to take more precautions, not
| less, just because we, the living, won the antibody
| lottery. At the end of the day this is a highly
| infectious + somewhat deadly disease that adds up to one
| deadly pandemic. If your point is that only another few
| million will die if we let it run rampant vs all of
| humanity, I don't disagree with you but urge you to
| examine what it means to let millions of people die in
| this case.
| weaksauce wrote:
| > For practical purposes, do you want to count these
| symptom-free infections in that calculation?
|
| well it possibly changes the calculus of how many people
| could potentially be a carrier of the virus. if that many
| people had the disease enough to have some antibodies
| even with all the extreme measures put into place it is
| possible this virus is even more contagious than we
| thought it could be. i don't know and i feel like we
| won't know because the study of transmission is woefully
| hard to do. going into this we didn't even know
| specifically how the flu was transmitted other than hand
| waving ways(maybe on the surface, maybe aerosols, maybe
| particles). our research has improved but it's still not
| great.
| IgorPartola wrote:
| Agreed. This tells us that we need to do 100 more studies
| and not much else. It doesn't conclude that the people
| with these antibodies are actually any better off and not
| getting sick or not transmitting the disease. As you
| point out they might be worse off. Everyone here is
| getting very excited about this study because I suspect
| people think this means that everyone already had COVID
| so there is less reason to worry. This study says nothing
| of the sort.
| markwkw wrote:
| We know the mortality rate to a degree. Mortality rate is
| number of deaths over the number of instances. If you have
| limits on the accuracy of the denominator you have limits
| on the accuracy of mortality rate. Sero studies like this
| one suggest to how many infections of the virus we have
| been missing.
| IgorPartola wrote:
| This study doesn't suggest any number of infections. We
| don't know if by any definition people who have these
| antibodies had a COVID infection or not.
|
| We know deaths / symptomatic infections really well due
| to the large numbers involved.
| BlueTemplar wrote:
| Wouldn't mortality rate drop off a cliff once we have herd
| immunity?
| IgorPartola wrote:
| The current answer to me seems to be that we do not know
| one way or the other. The hope is that it will but we are
| just now starting to get some data on how effective
| vaccines are at preventing transmission (Pfizer seems
| effective, others have no conclusive data AFAIK), we
| don't know what herd immunity actually is (Fauci
| estimates between 70 and 95% vaccinated; 70% is possible
| without vaccinating children, 95% is not. In the US you
| have enough anti-vaxxers to prevent herd immunity from
| ever happening even at 70%), we don't know how long the
| vaccine is good for (current estimate is at least 6
| months but no clue if it is more), and we don't know what
| other mutations will show up. The peachy scenario is that
| we vaccinate everyone super quickly while keeping social
| distancing and masks to not have any new variants develop
| and herd immunity can be achieved with very low
| percentages. The other scenario is that we take our time,
| dozens of vaccine resistant variants pop up in the
| meantime and it never goes away because a virus can
| mutate and spread more quickly than we can play whack a
| mole.
| lazide wrote:
| It may also be telling us that the antibody tests and our
| understanding of how antibodies help in protecting against
| severe Covid may be wildly wrong. Vaccine data indicates
| overall immune response is protective, and can be successfully
| prompted, and that is correlated with antibody levels, but
| there may be more going on here.
| qbasic_forever wrote:
| Yeah I saw a recent study that showed in monkeys the T cell
| response didn't really matter or do much for COVID-19. They
| looked at monkeys which had an illness that depleted their T
| cells and compared to healthy monkeys to see how an infection
| of COVID-19 went and saw surprisingly the T-cell depleted
| monkeys weren't much worse off. This is somewhat of a
| surprise since it was assumed T cells would be an effective
| way to neutralize COVID-19. Ultimately it just shows there
| are many more mysteries to this virus than solid answers.
| Preprint here:
| https://www.biorxiv.org/content/10.1101/2021.04.02.438262v1
| maxerickson wrote:
| No, it's not telling us that.
|
| The antibody tests are designed with high specificity for
| particular antibodies, this study went out of their way to
| look for any reactivity.
| lazide wrote:
| Designed for, but except in a very small number of cases
| not actually validated in the field to perform that way -
| and the specific antibodies may not be a useful indication
| of a useful immune response in the way we think it is. We
| do not have the actual evidence to demonstrate it.
| maxerickson wrote:
| Which widely used antibody tests where not checked and
| validated against uninfected blood/individuals?
| lazide wrote:
| Pretty much any of those actually available to most
| people early on? [https://www.bloomberg.com/news/articles
| /2020-06-16/coronavir...] or even as of November 2020? [h
| ttps://www.cdc.gov/coronavirus/2019-ncov/lab/resources/an
| ti...]
|
| The emergency use authorizations allowed anyone who
| plausibly had a test to market it, even if it had not
| been independently validated in any way by anyone. Many
| folks just bought what they could find, even if it didn't
| have an emergency use authorization.
|
| Combined with porous borders, e-commerce and the
| internet, lack of consequences for someone in China to
| ship junk here? We got buried in (at best) untested junk,
| and often outright scams.
|
| This has resulted in a rather predictable disaster when
| it comes to data and awareness - very few of the tests
| are being cross referenced to other data sources or
| tested against an independently verified data source, and
| even fewer (if any) are being evaluated by a independent
| party. The vast majority of tests in April have since
| been removed from authorization because they don't work,
| don't work well enough, etc. You can read a very nice
| paper from the FDA here summarizing it.
| [https://www.nejm.org/doi/full/10.1056/NEJMp2033687]
|
| As far as I am aware, there is still no clear picture on
| which tests have actually been validated, by whom, and to
| what extent against what data set. Will they pick up
| variants, and if so which ones? With what accuracy? What
| are common field errors (collection problems, etc) that
| can lead to problems? What about manufacturing variance
| and supply chain issues?
| maxerickson wrote:
| So I used the sophisticated strategy of searching for the
| first test on https://www.fda.gov/medical-
| devices/coronavirus-disease-2019... and up pops
| https://jcm.asm.org/content/59/1/e02104-20 (it's a study
| validating the sensitivity and specificity of the test).
|
| You've raised the bar a long ways from _except in a very
| small number of cases not actually validated in the field
| to perform that way_ to a comprehensive analysis of all
| tests that have even maybe been available.
|
| Of course, the 'very small number of cases' makes it
| impossible to argue without doing a comprehensive study,
| but it's clear enough that the widely used commercial
| tests were developed with the idea that they should
| minimize false positives and tested against pre-Covid
| serum.
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