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Until a vaccine is found, 60-70% of the population will need to get infected for "herd immunity". While at the same time making sure infection doesn't grow expo
by dirkt 6y ago
Until a vaccine is found, 60-70% of the population will need to get infected for "herd immunity". While at the same time making sure infection doesn't grow exponentially, and overwhelms the health system.
Loosening the lockdown, and being prepared to row back, will achieve that if done carefully, while at the same time getting the economy slowly back to normal.
And that probably are a lot more people are already infected without symptoms will help with that.
Trying to somehow contain the infection won't work, because it will just get carried in from the outside again, eventually.
- lnsru 6y agoSorry, I have no knowledge on virology topics. But this “herd immunity” thing is a complete nonsense. Politicians may repeat it as long as they want, but it still makes no sense. 50 million people must be infected, 1,5 million will die. It will take many years. While immunity very probably(????) disappear after months. Asian countries had many different viruses in the past, all of the contained. Why is it so difficult to follow their path?
- deleted 6y ago[deleted]
- SpicyLemonZest 6y agoAsian countries have not contained all viral outbreaks in the past. In both 1957 and 1968, Asian-origin flu epidemics killed millions. It's possible that containment could have been achieved if every country had swiftly followed Korea's example in early February, but there's no precedent for containing a human-to-human transmissible disease with millions of cases across the world without a vaccine.
- lnsru 6y agoThank you very much. I am too young to remember these events. But I am also confident, that current technology is better than 50 years ago.
- cipher_system 6y agoHow do you know it's complete nonsense if you have no knowledge on the subject?
- lnsru 6y agoHow do you start? Write invitation letters with date and time to first batch to be infected? Nonsense it is because it’s barely doable. The people will simply leave country unless one puts military on the borders.
- cipher_system 6y agoWell, unless you have a vaccine, the virus does all of the work for you. Also, you can't really leave a country now anyway, and even if you could, the virus would be at the destination. The herd immunity is not really something that you do but more of an unavoidable side effect. I'm not sure that we have much of a choice now that we are well beyond the point of containment.
- 6510 6y agoI think the analogy says more about the person using it than the actual topic. If it was appropriate to compare people with... well... cows? Why not slaughter the lot and start over? Or take the stupid analogy to the next level and talk crop engineering? There! The solution has been staring us in the face all along.... or wait...
- nradov 6y agoThat's just the terminology used in epidemiology. Don't read anything into it.
- 6510 6y agoOh but I do! Group immunity or collective immunity will do just fine. I really don't care how popular this zoology terminology is. For me taxonomy works like: A pack of wolves, a flock of birds and a herd of cattle. Beware when they start calling you [say] a consumer.
- wool_gather 6y agoHerd immunity is a real phenomenon -- it's the strategic goal behind widespread vaccination, and the reason that vaccination controls disease even if less than 100% of the population takes the vaccine or gets immunity from it. That said, I think you're right to be skeptical of the "let everyone get it and we'll have natural herd immunity" idea.
- standardUser 6y agoYou don't know how many people are currently immune. Or how immunity even works for this virus. No one does. Zika was rendered mostly harmless by herd immunity before experts even knew what happened. I don't see what is gained by making armchair proclamations as if you know something the rest of us don't. You don't even seem to know what you don't know.
- sdffdsfdsfsddsf 6y agoThe death rate is certainly lower than 3%.
- wool_gather 6y agoWorldwide at this moment total (cumulative) deaths over total (cumulative) cases is nearly 7%, with considerably over half the total cumulative cases still active. Granted that we know that there are many undiagnosed cases, but we don't have a clear picture how many. There's no basis right now for your assertion. https://www.worldometers.info/coronavirus/ https://www.worldometers.info/coronavirus/
- sdffdsfdsfsddsf 6y agoThe basis is studies of closed communities. Here in Germany there was a study of a whole village (testing everyone), that found a death rate of 0.37%. Other interesting data sets may be Diamond Princess cruise ship, Theodore Roosevelt carrier, or Health Care Workers. So saying there is "no basis" is a bit rich. There may still be uncertainty. Edit: this (just googled) article cites Diamong Princess to lead to an estimate of 0.5% death rate https://www.sciencenews.org/article/coronavirus-outbreak-diamond-princess-cruise-ship-death-rate https://www.sciencenews.org/article/coronavirus-outbreak-dia... (the percentage of deaths on the DP was higher, but the passengers were also comparatively old on average). Edit 2: lol for the downvote. What the fuck? Edit 3: about the study in Germany https://www.theblaze.com/news/german-study-shows-coronavirus-mortality-rate-five-times-lower-than-widely-reported-numbers https://www.theblaze.com/news/german-study-shows-coronavirus... (don't know "The Blaze", but if you care, you can google for better sources - google for "Streeck"). Edit 4: Theodore Roosevelt carrier https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_on_USS_Theodore_Roosevelt https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_on_U...
- bpodgursky 6y agoThere are a lot of people on HN (and the internet at large) who view any statement adjusting-downward death rates as "COVID denialism", and will reflexively downvote attempts to correct in that direction. In the most charitable reading, you could view them akin to the CDC and masks, trying to keep the public slightly misinformed for the greater good (preserve mask supplies for hospitals). In the least charitable reading, there are a lot of depressed and angry people on the internet, who want to believe that this disease is truly civilization-ending, and attack any opposing narrative. Either way, I would not take it personally, or as a judgement on your actual quoted facts.
- notechback 6y agoHerd immunity is not just a buzzword. We have two options to reduce the harm of infectious diseases: eradicate them or build herd immunity. The first option has become impossible with this virus that's now truly global and likely much more spread than is known. Therefore herd immunity is the ONLY option. The question then is how to get as many people as possible immune - you'll either need a vaccine or many need to get the infection and survive. A vaccine is not on the horizon for another 6-12 months, so the best course of action is to build the number of survivors. What brings death? Mainly the sudden onslaught on the health system. If there is no bed, respirator, blood supply, ... Left then you're much more likely to have patients die than if you have a hospital at regular capacity. There are some that WILL for but by slowly building immunity (i.e. allowing some parts of the population to get exposed) you avoid the high death toll of an unmanaged outbreak. So if total eradication is impossible, slow infection rates are better than none. Why? Because if you don't build the immunity you will again have violent outbreaks killing many. And you simply can't lock everyone at home for another 6 months.
- wl 6y ago> If there is no bed, respirator... Most of the people who go on respirators die. If the health system is going to be our weapon here until the vaccine is developed, we need to find ways to manage the disease before it gets to the point where we intubate people. Remdesivir might be that drug, but we're unlikely to have the kind of supply needed for what you propose until after the first vaccines potentially may be available.
- usaar333 6y agoThere is no reason you can't keep a disease at a very low level (to the point any given person is unlikely to get the disease over their lifetime) via testing, contact tracing and quarantine. Iceland and South Korea both prove you can in fact.
- rootusrootus 6y agoIceland is tiny and it is a little early to proclaim SK an unqualified success. If the only way to keep the disease at a very low level is to have a new normal of strong quarantine indefinitely, then you are asking for something unrealistic. Even more so in western democracies where people are accustomed to a great deal of personal freedom.
- wh1t3n01s3 6y agoImmunity does not disappear. The virus could mutate, but not likely and surely would become less deadly. Herd immunity is a fact. It is natural. And we’ll probably reach it sooner than you think. I hope like everybody for a vaccine but I personally don’t think we’ll make it on time enough.
- anotheryou 6y agoWe can roughly estimate how long that will take if we stay at R=1. That's maybe 100k new infections monthly in germany. Meaning it takes ~40 years to reach 60%. (83000k*0.6/100k/12) Maybe it's less if you can get more aggressive with more immunity, but even if I'm wrong by a factor of 10 it's still years and the vaccine is the more realistic bet.
- standardUser 6y agoWe can roughly estimate precisely nothing until we know how many people have been infected, how many are immune and how long immunity lasts. We currently know none of those things.
- anotheryou 6y agoI took the best case scenario: all tested become immune for ever. If you want add a 3x factor for unreported cases and you're still at 10 years waiting time. Estimates make sense, especially if they proof your point even if you are off by a factor of 10.
- sarbaz 6y agoOne way to shorten the time is to constantly increase hospital capacity, so that in each month lets you infect more people. Especially if plasma donations turn out to work to reduce severe cases. Another way is to separate young people from old people more effectively. Then you might be able to permit 1m young people to be infected each month with the same hospital budget we have today
- majewsky 6y agoThat's assuming that the only two outcomes of a SARS-2 infection are "dead" and "completely recovered". There are case reports of young and otherwise healthy adults who survived SARS-2, but where a CT shows the lung tissue mostly obliterated. Sure, they survive, but running a marathon or going on that diving vacation might be a sudden death sentence for them.
- rv-de 6y ago60% to 70% refers to an R0 of about 3. But the R0 is more likely to be around 6. That means you need 5/6th of a population to be immune - that's about 80% to 90%. UPDATE: "Results show that the doubling time early in the epidemic in Wuhan was 2.3–3.3 days. Assuming a serial interval of 6–9 days, we calculated a median R0 value of 5.7" https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article A herd immunity strategy involving fast immunization by continuing business as usual would then involve an R0 > 5.
- standardUser 6y agoYou're making up numbers. We don't know the R0 and likely won't for some time.
- rv-de 6y ago"Results show that the doubling time early in the epidemic in Wuhan was 2.3–3.3 days. Assuming a serial interval of 6–9 days, we calculated a median R0 value of 5.7" https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article A herd immunity strategy involving fast immunization by continuing business as usual would then involve an R0 > 5.
- standardUser 6y agoThere have been several studies that have come up with different numbers. I guess we can calculate some interesting stuff based on the range, but it's a really big range (I've seen somewhere in the range of 1.5 to 7 in various articles/studies).
- usaar333 6y agoR0 is environment dependent. It is probably in the 2-3 range for say California using hospitalization data.
- Theodores 6y agoThere is not going to be a vaccine and there is not going to be herd immunity. You can't count on either of those outcomes any more than you can count on there being a vaccine and herd immunity for the common cold. However you can make it mandatory for anyone with cold/flu symptoms to self-isolate rather than do the manly thing of bring it into an office and work through it. You can also make it so that people have to go into quarantine after international travel. You can also do some testing. Rabies has been kept outside of the UK for decades by the quarantine approach. Pets can go one way from the UK to the rest of the world quite freely but on the way back they have to be quarantined. With rabies free Ireland an exception can be made. With this approach we can avoid the indefinite lockdown required until the holy vaccine is found.
- vikramkr 6y agoI think a vaccine is quite likely to be developed within the next couple years, the virus isn't as complex or difficult as influenza or hiv to target and we have some well defined targets to go after, as well as numerous vaccines already in clinical trials.
- blablablub 6y agoUnfortunately herd immunity does not work. Germany has ~83m pple x 70% = 58m need to be infected for herd immunity The ages 65+ you want to protect and don't infect ~17m That reduces the people which naturally get herd immunity to (83m- 17m) x 70% = 46m How do you want to infect the remaining 12m pple? By force? If you go by likelyhood of death by age, basically everyone below the age of 45 has to be infected to protect the elderly.