8 ms·

We've found pre-existing T-cell immunity in many individuals (cross-protection from other coronaviruses?) so even if we don't have long-term perfectly sterilizi

We've found pre-existing T-cell immunity in many individuals (cross-protection from other coronaviruses?) so even if we don't have long-term perfectly sterilizing immunity, the odds are stacked in favour of this becoming just another winter respiratory disease once some level of herd immunity kicks in. There is a lot of confusion around herd immunity. Think of it more like an equilibrium state than an elimination state. It is where this virus will end up whether we have a perfectly sterilizing vaccine or not. https://www.bmj.com/content/370/bmj.m3563 https://www.bmj.com/content/370/bmj.m3563

Retric 6y ago
An effective vaccine in the near future is a much better option than natural herd immunity due to the lives lost. Longer term it gets interesting because young people are at a dramatically lower risk of death and older people will have been exposed several times. So, if things go endemic it’s likely for long term annual deaths to be dramatically lower. PS: The error bars in what you linked are very wide repressing significant uncertainty around those tests.
- ethbr0 6y ago
  As you noted, a vaccine allows us to target immunity, typically by risk profile, as we currently do with common cold viruses. Herd immunity does not. So while less virus circulating due to greater population immunity (and therefore lower individual risk of infection) is good, it doesn't help when SARS-CoV-2 does chance into a nursing home.
WildParser 6y ago
Yeah, the mathematics around herd immunity are often misused. People seem to always assume independent identical random variables. Corona Virus are seasonal - infections highly locally clustered. The spreading might refuse to follow slow brownian motion of the herd. If e.g. an aircondition blasts an entire room of people with bad air, how much do herd effects really help? Does the term "herd immunity" make sense for a seasonal virus at all?
- maxerickson 6y ago
  Does the term "herd immunity" make sense for a seasonal virus at all? Yes. For instance, one of the benefits of widespread flu vaccination is that it slows the rate that the virus spreads at. Herd immunity is just the threshold where enough people have immunity that the spread diminishes. That we don't necessarily reach the threshold doesn't make the lesser effect useless.
  - cies 6y ago
    > Herd immunity is just the threshold where enough people have immunity that the spread diminishes. So herd immunity is not about immunity. Quite a misnomer then! Always thought herd immunity protected those still vulnerable, but according to you it merely means the vulnerable may merely be having a few more healthy hours falling sick non the less.
    - singemonkey 6y ago
      You probably shouldn't rely on some random HN poster for your definition of what herd immunity means. It's a well defined term in the epidemiological field, and definitions are readily available via sites such as Wikipedia and search engines.
    - enkid 6y ago
      With more individuals having immunity, it's likely the disease won't reach as many individuals who are vulnerable because they lack immunity and have underlying medical conditions. It's the level when outbreaks can stay localized instead of spreading to everyone.
    - usrusr 6y ago
      It is about immunity, just not about the individual. It means that if the virus spreads to a non-immune individual from the outside the spread inside the herd will eventually stop (but we don't know when). It can still reach an arbitrary number of non-immune individuals, but given infinite time and an infinite herd, it will eventually stop. Low level zero friction school physics analogy: think of a ball rolling onto an inclined plane. If the plane is angled upwards the ball will slow down and eventually stop rolling further upwards, if the plane is angled downwards it will just continue accelerating forever. But in the upwards case no place on the plane is truly safe from getting reached by the ball, because speed and angle is not specified. Herd immunity means that the slope is upwards, but the velocity would still be an open-ended random distribution. A more accurate model for virus spread would replace momentum with dice rolls and slope with success thresholds, but that's just more difficult to imagine (unless your biography contains a phase of obsessing over p&p rpg rules).
mns 6y ago
> the odds are stacked in favour of this becoming just another winter respiratory disease once some level of herd immunity kicks in. The thing is, looking at the seasonality of the other strains of coronaviruses, you can see how it kind of looks to what we had this year (only worse as no one was ever infected with this). See Fig. 1 here : https://smw.ch/article/doi/smw.2020.20224 https://smw.ch/article/doi/smw.2020.20224 But people do sure like to blame and shame everyone in Europe and the US as if 1 billion people in the Northern hemisphere are somehow all to blame they weren't compliant enough. Viruses will doo what they always did.
- garmaine 6y ago
  Except there are populous, prosperous countries (e.g. Taiwan) which have kept the virus 100% in check and eliminated it from community spread. I do blame other countries for not doing enough.
- ttul 6y ago
  Viruses can be stopped. See South Korea, China, and Taiwan for a few examples. Sure, the Chinese approach would not be possible in a democracy. But Taiwan? My friends there continue to live a very free life, yet COVID-19 is nowhere to be seen... Arguably, they are much freer than we are in North America and Europe right now.
  - deleted 6y ago
    [deleted]
  - pessimizer 6y ago
    And New Zealand. And somehow Australia just reported their first day with no new cases in 6 months.
    - kgc 6y ago
      Both New Zealand and Australia performed strict lockdowns. The US/Europe is unlikely to be able to achieve the same level of compliance needed to make those successful.
espresso_enigma 6y ago
> just another winter respiratory disease Yeah, but this one can cause lasting cardiovascular and nervous system damage in a significant number of people, in addition to permanent lung damage. It's not just another respiratory disease.
- ACow_Adonis 6y ago
  Do you (or anyone else) have scientific numbers, sources and/or comparisons for: a) quantification and definition of lasting cardiovascular/ nervous system damage b) quantification of a significant number of people c) comparisons to rates comparable to other respiratory diseases (like influenza strains or the bird flu strains etc. ) Understand I ask this not as a coronavirus skeptic, but as a science-literacy proponent who hasn't yet read any reliable source or study for the claim you're making.
  - rusk 6y ago
    I think the burden of proof is on you since you are the one contradicting the prevailing thought. You must “reject the bull hypothesis” as it were. Personally I have seen one case of a 17 y/o with lingering nerve damage covered on national news.
    - ACow_Adonis 6y ago
      I fundamentally disagree that I'm conflicting with prevailing thought (at least of medical experts), both because I don't accept that it's prevailing thought, but also because I'm just being proactively and constructively sceptical. If someone proclaims to know the long term effects of a recent novel virus, that's an interesting claim. then they compare the outcomes to other viruses (or declare its fundamentally different), that's also interesting. I've seen news articles about specific cases, and alarmist tabloid-esque case studies, but as someone who actually reads medical studies, I don't let media or hand-picked cases set my opinion, because in a pandemic with countless millions infected, and with a disease that disproportionately affects co morbid patients, of course one will find individual reports of bad cases and complications. But the information I asked for is presumably the minimum required for your claim to be justified. And if it is so "prevailing", it would be widespread and easily findable, whereas I have yet to see a single source that has them.

Retric 6y ago

An effective vaccine in the near future is a much better option than natural herd immunity due to the lives lost. Longer term it gets interesting because young people are at a dramatically lower risk of death and older people will have been exposed several times. So, if things go endemic it’s likely for long term annual deaths to be dramatically lower. PS: The error bars in what you linked are very wide repressing significant uncertainty around those tests.

ethbr0 6y ago
As you noted, a vaccine allows us to target immunity, typically by risk profile, as we currently do with common cold viruses. Herd immunity does not. So while less virus circulating due to greater population immunity (and therefore lower individual risk of infection) is good, it doesn't help when SARS-CoV-2 does chance into a nursing home.

WildParser 6y ago

Yeah, the mathematics around herd immunity are often misused. People seem to always assume independent identical random variables. Corona Virus are seasonal - infections highly locally clustered. The spreading might refuse to follow slow brownian motion of the herd. If e.g. an aircondition blasts an entire room of people with bad air, how much do herd effects really help? Does the term "herd immunity" make sense for a seasonal virus at all?

maxerickson 6y ago
Does the term "herd immunity" make sense for a seasonal virus at all? Yes. For instance, one of the benefits of widespread flu vaccination is that it slows the rate that the virus spreads at. Herd immunity is just the threshold where enough people have immunity that the spread diminishes. That we don't necessarily reach the threshold doesn't make the lesser effect useless.
- cies 6y ago
  > Herd immunity is just the threshold where enough people have immunity that the spread diminishes. So herd immunity is not about immunity. Quite a misnomer then! Always thought herd immunity protected those still vulnerable, but according to you it merely means the vulnerable may merely be having a few more healthy hours falling sick non the less.
  - singemonkey 6y ago
    You probably shouldn't rely on some random HN poster for your definition of what herd immunity means. It's a well defined term in the epidemiological field, and definitions are readily available via sites such as Wikipedia and search engines.
  - enkid 6y ago
    With more individuals having immunity, it's likely the disease won't reach as many individuals who are vulnerable because they lack immunity and have underlying medical conditions. It's the level when outbreaks can stay localized instead of spreading to everyone.
  - usrusr 6y ago
    It is about immunity, just not about the individual. It means that if the virus spreads to a non-immune individual from the outside the spread inside the herd will eventually stop (but we don't know when). It can still reach an arbitrary number of non-immune individuals, but given infinite time and an infinite herd, it will eventually stop. Low level zero friction school physics analogy: think of a ball rolling onto an inclined plane. If the plane is angled upwards the ball will slow down and eventually stop rolling further upwards, if the plane is angled downwards it will just continue accelerating forever. But in the upwards case no place on the plane is truly safe from getting reached by the ball, because speed and angle is not specified. Herd immunity means that the slope is upwards, but the velocity would still be an open-ended random distribution. A more accurate model for virus spread would replace momentum with dice rolls and slope with success thresholds, but that's just more difficult to imagine (unless your biography contains a phase of obsessing over p&p rpg rules).

mns 6y ago

> the odds are stacked in favour of this becoming just another winter respiratory disease once some level of herd immunity kicks in. The thing is, looking at the seasonality of the other strains of coronaviruses, you can see how it kind of looks to what we had this year (only worse as no one was ever infected with this). See Fig. 1 here : https://smw.ch/article/doi/smw.2020.20224 https://smw.ch/article/doi/smw.2020.20224 But people do sure like to blame and shame everyone in Europe and the US as if 1 billion people in the Northern hemisphere are somehow all to blame they weren't compliant enough. Viruses will doo what they always did.

garmaine 6y ago
Except there are populous, prosperous countries (e.g. Taiwan) which have kept the virus 100% in check and eliminated it from community spread. I do blame other countries for not doing enough.
ttul 6y ago
Viruses can be stopped. See South Korea, China, and Taiwan for a few examples. Sure, the Chinese approach would not be possible in a democracy. But Taiwan? My friends there continue to live a very free life, yet COVID-19 is nowhere to be seen... Arguably, they are much freer than we are in North America and Europe right now.
- deleted 6y ago
  [deleted]
- pessimizer 6y ago
  And New Zealand. And somehow Australia just reported their first day with no new cases in 6 months.
  - kgc 6y ago
    Both New Zealand and Australia performed strict lockdowns. The US/Europe is unlikely to be able to achieve the same level of compliance needed to make those successful.

espresso_enigma 6y ago

> just another winter respiratory disease Yeah, but this one can cause lasting cardiovascular and nervous system damage in a significant number of people, in addition to permanent lung damage. It's not just another respiratory disease.

ACow_Adonis 6y ago
Do you (or anyone else) have scientific numbers, sources and/or comparisons for: a) quantification and definition of lasting cardiovascular/ nervous system damage b) quantification of a significant number of people c) comparisons to rates comparable to other respiratory diseases (like influenza strains or the bird flu strains etc. ) Understand I ask this not as a coronavirus skeptic, but as a science-literacy proponent who hasn't yet read any reliable source or study for the claim you're making.
- rusk 6y ago
  I think the burden of proof is on you since you are the one contradicting the prevailing thought. You must “reject the bull hypothesis” as it were. Personally I have seen one case of a 17 y/o with lingering nerve damage covered on national news.
  - ACow_Adonis 6y ago
    I fundamentally disagree that I'm conflicting with prevailing thought (at least of medical experts), both because I don't accept that it's prevailing thought, but also because I'm just being proactively and constructively sceptical. If someone proclaims to know the long term effects of a recent novel virus, that's an interesting claim. then they compare the outcomes to other viruses (or declare its fundamentally different), that's also interesting. I've seen news articles about specific cases, and alarmist tabloid-esque case studies, but as someone who actually reads medical studies, I don't let media or hand-picked cases set my opinion, because in a pandemic with countless millions infected, and with a disease that disproportionately affects co morbid patients, of course one will find individual reports of bad cases and complications. But the information I asked for is presumably the minimum required for your claim to be justified. And if it is so "prevailing", it would be widespread and easily findable, whereas I have yet to see a single source that has them.