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Ask HN: Has any study been done doing a random sampling of a population using an antibody immunity test? It seems the natural next step given we have such a tes

• phaemon 7y ago
  As an alternative point of view: who cares? We know for a fact that ICUs are being overloaded with cases and morgues are overwhelmed with the dead. Arguing over exact figures is like quibbling over your exact velocity as you're falling off a cliff. Finding some prettier numbers won't change the reality of the situation, no matter how convincingly you argue your case.
  • nothrabannosir 7y ago
    People are talking doomsday scenarios, on this very forum. Getting some hard facts would really help temper the hysteria, or allow people to prep further appropriately. We’re planning for more than the next three days here.
  • rubidium 7y ago
    An alternative to your alternative: science and medicine still work. Let's try and make it better. The better we understand our situation the better we can react appropriately. Yes, it's really bad in a few places right now. It looks like it's going to be really bad in a lot more places in the next 15-20 days. How _long_ will it be really bad for and for how _many_ people will it be really bad are important questions to understand. Don't let the dire situation make you irrational.
    • phaemon 7y ago
      I'm not being irrational; you are. I accept what I'm seeing as the reality of the situation. You appear to be looking for numbers that will tell you things are different to the observed reality. That's my point.
      • Lewton 7y ago
        You don't KNOW what the reality of the situation is right now without knowing how many people are actually infected
      • rimliu 7y ago
        The observed reality where? Bergamo? South Korea?
        • VBprogrammer 7y ago
          The situation in South Korea is clearly an outlier. Even knowing exactly the steps which have drastically slowed the growth of the virus in South Korea is about as useful as knowing last week's lottery numbers at this point.
          • rimliu 7y ago
            Taiwan, Hong Kong. You can even say that Italy is an outlier too.
          • easytiger 7y ago
            It's not an outlier. Germany has even lower numbers despite doing even less than Korea. Italy and the UK book the death of anyone who died testing positive as a covid19 death. The UK won't release any figures beyond that. Not even hospitalisation data. Studies in Italy show fewer than 15% of those deaths might be specifically caused by it. > On re-evaluation by the National Institute of Health, only 12 per cent of death certificates have shown a direct causality from coronavirus, while 88 per cent of patients who have died have at least one pre-morbidity - many had two or three,” he says.^ In fact the average comorbiditities is 2.7. mean age of death is 79.5 years. Median 80.5. ^ https://www.telegraph.co.uk/global-health/science-and-disease/have-many-coronavirus-patients-died-italy/ https://www.telegraph.co.uk/global-health/science-and-diseas...
      • creato 7y ago
        If many more people are infected with mild symptoms than currently thought, that could have large implications for how long economic shutdowns need to last.
  • Lewton 7y ago
    If you had a random sample from two weeks ago and one from today, you think this provides zero information on how to react now?
    • phaemon 7y ago
      Yes, that's what I think. The actions two weeks ago were: Shut down everything except essential services, isolate everyone as much as possible, throw as many resources as possible at your health service. Even then, they will be overwhelmed at some point. The same actions apply today. What's changed?
      • Lewton 7y ago
        Which country are you even talking about? If you think the US is literally doing everything they can, have you looked at what the lockdown in Italy looks like? If you have random sampling from two weeks ago and today, you might find out that you won't have to go to the same extremes as italy, or you might find out that military should have been on the streets a week ago and putting them on the streets now is a good idea
        • phaemon 7y ago
          I'm talking generally about all developed countries (I know what in many developing countries a lockdown will simply be impossible). I certainly don't think the US has done everything it can. Quite the contrary - it's no surprise to me at all that it is now top of the leaderboard in recorded cases. The US had to go to at least the extremes of Italy, and it didn't, so you'll end up with many more deaths than you would otherwise have had. The US could just have looked at what was actually happening in Europe to establish what it needed to do. Arguing over the numbers is exactly what caused the inaction in the first place.
          • Lewton 7y ago
            Ok, then let's talk Europe. Denmark has been in a early and disciplined lockdown for 3 weeks. The amount of deaths per day seem to have stabilized. The Hospitals are not overrun When should Denmark end the lockdown? (And if Denmark had a random sampling from two weeks ago, and one from today, would they be better positioned to know when to end the lockdown or not?)
  • rimliu 7y ago
    Everybody should care. The most important thing, knowing the situation would enormously help with shaping up the response. If 0.0005% of the population had COVID-19 would require different actions compared to a situation where 30% had it. Not everywhere ICUS are being overloaded and morgues are overwhelmed with the dead. And ignorance was the first reason why it happened where that's the case. So anything that could decrease the ignorance should be met with open arms.
    • phaemon 7y ago
      > If 0.0005% of the population had COVID-19 That's exactly what I mean. There is no scenario where that is the case. If your numbers tell you that, your numbers are wrong. The actions are the same regardless: shut down everything except essential services, isolate everyone as much as possible, throw as many resources as possible at your health service. Even then, they will be overwhelmed at some point. What numbers exactly would lead you to a different course of action, based on what we have already observed?
      • rimliu 7y ago
        So, you did the testing and know the true numbers? How's that?
        • phaemon 7y ago
          Because if the number was 0.0005% you wouldn't see ICUs and morgues overwhelmed (why don't you calculate how many people that is for your country?) And, again, that's my point: you're asking why it can't be a ridiculously small number when it should be obvious from the reality of the situation that it isn't!
          • rimliu 7y ago
            Sorry, you make zero sense. First of all, not everywhere are ICUS and morgues overwhelmed. Some towns in Italy and Spain are hit bad, South Korea manages it without even having lockdowns. Second, and that's my point: you can have the same result with two very different scenarios: either a lot of people have/had it but in the vast majority of the cases it goes without symptoms at all. So when a big part of the population gets infected only then you start noticing "ICUs being overwhelmed". The second scenario is: it causes serious problems for a substantial part of the infected so even the small number of those who got the virus will flood the hospitals. And those two scenarios require different responses.
  • rcxdude 7y ago
    Because it makes a hell of a lot of difference if we are seeing those numbers in the ICU when 5% of the population is infected or 50% is infected. One means the situation is going to get way way worse in the future and one means we're probably nearing the peak now.
  • phaemon 7y ago
    Actually, I've changed my mind. I still don't think an antibody test should be a prerequisite for current action, but I think it will be very useful for deciding what to do in a few weeks.
    • Lewton 7y ago
      That's the point I was trying to make (quite clumsily, I agree). I hope I didn't give the impression that I expected the numbers to prove that we are overreacting. Having a reasonable idea of how many people have been infected will help when trying to avoid a second wave of infections
  • vikramkr 7y ago
    3 blue one brown had a great video on exponential growth that detailed how a 10% difference in the numbers is the difference between being halfway there and having orders of magnitude to go. As I'm sure you're aware, the point of the numbers isn't to change the reality of the situation, it's to understand what that reality is. And the people that care are epidemiologists and leaders with decades of experience fighting pandemic after pandemic. You know, people that know what they're talking about? Might be worth trying to spend time actually learning how the people that are spending day and night trying to save your life and the lives of your loved ones do their work before dismissing them as useless. https://youtu.be/Kas0tIxDvrg https://youtu.be/Kas0tIxDvrg
    • phaemon 7y ago
      I didn't. Try reading what I wrote. I'm dismissing half-brained idiots who try to downplay the seriousness of the situation by playing with numbers while ignoring what those numbers mean. I don't need any self-righteous advice from you.
• moviemove 7y ago
  Not a single mention of the disastrous pollution caused by the disposal of millions of non-biodegradable single-use masks into landfills https://projecteve.com/organizing-tech-tools-for-work/#comment-586225 https://projecteve.com/organizing-tech-tools-for-work/#comme...
• fsh 7y ago
  Probably the false-positive rate of antibody tests would be a big problem as long as only a small fraction of the population is infected. From what I've read, the specificity of such tests is way worse than for RNA-based tests.
  • ImaCake 7y ago
    Last I checked they had a roughly 10% false positive rate. So if 1 in 1000 people were infected but you tested all 1000 with an antibody assay, you would get 100 positives, and probably one of them is actually infected. Basically useless for mass screening. The gold standard RT-PCR assay has basically zero false positives, but requires experienced personnel and expensive reagents to do en-mass.
    • foobarian 7y ago
      I keep seeing news articles along the lines of "People getting reinfected" "In 5% of cases recovered patients tested positive for COVID-10 2 months later" "Asymptomatic individuals test positive for COVID anyway" Yeah very mysterious indeed :)
      • rjsw 7y ago
        Why would you think that people couldn't get reinfected ? The virus won't just bounce off your skin after one has got into you. If it is present everywhere in the environment then you will keep getting infected, maybe faster than your immune system can deal with it. The end point to aim for in terms of immunity is that your immune system can deal with any level of viral load in the future without you becoming ill. Maybe combined with prophylactic drugs that help prevent the virus reproducing as fast within you.
    • vikramkr 7y ago
      But we wouldn't pick up any of the people who are now immune right?
      • ImaCake 7y ago
• fabian2k 7y ago
  They're planning to do exactly that in some (probably many) countries. But the antibody tests are just being developed and might be ready in the next weeks for larger scales. But you need to do this properly to get a representative sample, which takes a bit of time.
  • rubidium 7y ago
    Who is planning to do that? Any info available on that? I understand the need for a proper study, just surprised we're not seeing more on this.
    • evandijk70 7y ago
      The Dutch blood bank, Sanquin, is currently running a study now for 10,000 blood donors, to see if the Netherlands is close to achieving 'herd immunity'
    • Agathos 7y ago
      Germany: https://www.dw.com/en/germany-mulls-mass-testing-for-coronavirus-immunity-report/a-52940096 https://www.dw.com/en/germany-mulls-mass-testing-for-coronav... The original report from Friday, auf Deutsch: https://www.spiegel.de/wissenschaft/medizin/coronavirus-grosse-antikoerper-studie-soll-immunitaet-der-deutschen-feststellen-a-c8c64a33-5c0f-4630-bd73-48c17c1bad23 https://www.spiegel.de/wissenschaft/medizin/coronavirus-gros...
• xorfish 7y ago
  This will be important information in a few months when countries have lowered the new detected cases and the lift of harsh measures is considered. So there is still some time to get the data. At the current moment, they are not important for the decisions. However I want to caution anyone to expect a large proportion of the population to test positive in these tests. We know that South Korea was able to contain the spread before a significant proportion of the population was infected. A important part of the strategy was contact tracing. For contact tracing to work, you need to detect at least 1-1/R of cases. If we assume that other measures such as masks and limited social distancing pushed R down to 2 and assume they were able to trace 100% of contacts, then we still have only twice as many that are infected. If nobody of the cases that are still ongoing dies, we look at a lower bound of the IFR of 0.8%.
  • nostrebored 7y ago
    How can you say this? If it's significantly more infectious than we thought, that will obviously influence public policy as the r_0 will be radically decreased
    • xorfish 7y ago
      The number of people that are infected doesn't tell you that much about R0. You can get R0 from the increase in daily new deaths and the generation time between infections, given that the quality of care stays constant. Serological tests will tell you something about the early outbreak and how many cases where not detected and how high the infected fatality ratio really is. I have seen many people that still believe that the IFR is in the range of an average flu. With the data from South Korea, we can put a number at what we can expect the IFR to be if we make some optimistic assumptions. That is why I say that you should not expect that serological tests show that a large part of the population already had covid19 and that the IFR is much lower than we expect. They will show where exactly the IFR is.
• abraxas 7y ago
  Or even the Infection Fatality Rate. The only way to stop fumbling in the dark is to get a random representative sample tested. It’s not impossible there is a dark pool of great numbers of present and past infections that are causing people to overreact .
  • deleted 7y ago
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