5 ms·

I think the Dakotas are already at herd immunity

19 points by rossdavidh 6y ago

hamolton 6y ago
I agree with you that most susceptible populations have probably gotten it by now, especially among people living on reservations. It's hard to imagine that the real numbers would have reached 70%, though, considering the total COVID deaths per 100k population in the Dakotas is 184 & 181 compared to New Jersey's 229, although I guess NJ does have a larger old population. I always imagine as life on the gigantic old homesteading plots to be isolated, but I have no idea.
- mike_n 6y ago
  it does seem very plausible that undetected cases are several times higher than confirmed/symptomatic cases. and/or, perhaps when things start to spike locally people begin to take it seriously and change their behavior a bit -- distancing/masks were not very common in the Dakotas before the post-Sturgis wave.
ineedasername 6y ago
I'm not sure they're densely populated enough to easily know which X multiplier to apply to the positive rate. People speculate infection rates as high as 10x, I would speculate that multipliers of that sort will be positively correlated with population density, meaning a lower multiplier rate and further from herd immunity.
- brewdad 6y ago
  I think small towns could still replicate some of the exposure risk caused by population density since there will often be only one or two stores to buy groceries, generally located in the largest town in a larger rural area. People will gather in those stores in relatively dense numbers compared to the community at large. Mix in a reluctance to wear masks and determining the correct multiplier becomes more challenging.
  - ineedasername 6y ago
    Except I don't think small towns represent small-world networks: they are likely to be clustered within themselves with just a few links outside.
- rossdavidh 6y ago
  I absolutely believe the multiplier would be different in different places. The fact that the back-of-the-envelope calculation for the U.S. and Slovakia give similar answers, though, suggests that it may not be so different. But sure, definitely no reason to expect it so be exactly the same.
garciasn 6y ago
I appreciate the analyses but struggle with the dissemination of opinion pieces from those who do not work in public health policy or have a MD. Can someone please explain why we should give any weight to the musing of an EE software developer when this particular topic is so fraught with issue even from actual experts in the space?
- reducesuffering 6y ago
  Because the CDC said to not wear masks when this whole forum was citing papers and screaming that we should wear masks and wtf is the CDC doing?
  - redis_mlc 6y ago
    And WHO. And Fauci. And Oxford. And usually they doubled down when it was found out they were wrong. The only person I know of who is facing any kind of accountability is Gov. Newsom, who will very likely face a recall vote over destroying the Calif. economy while taking federal funds and flouting the lockdown he himself ordered. His ambition to run for US President dims as each day goes by.
  - jryb 6y ago
    The rationale that they gave at the time was that they feared people would buy up all the masks leaving hospitals undersupplied, and that people would think that wearing a mask meant that you wouldn't also need to distance yourself from others.
    - yostrovs 6y ago
      At the time, the rationale given was that masks don't work. The idea that people would go to Home Depot to buy up all the existing masks was a nonsense excuse later provided, since hospitals have their own supply mechanisms. Hoarding of toilet paper by the public did not cause a toilet paper shortage within hospitals.
    - reducesuffering 6y ago
      I'll let the US Surgeon General's words speak for themselves. Note that he has since deleted his tweet; I wonder why? "Seriously people- STOP BUYING MASKS! They are NOT effective in preventing general public from catching #Coronavirus, but if healthcare providers can't get them to care for sick patients, it puts them and our communities at risk! https://t.co/UxZRwxxKL9 https://t.co/UxZRwxxKL9" — U.S. Surgeon General (@Surgeon_General) February 29, 2020[0] Deleted tweet[1] [0]https://www.cnn.com/2020/02/29/health/face-masks-coronavirus-surgeon-general-trnd/index.html https://www.cnn.com/2020/02/29/health/face-masks-coronavirus... [1]https://twitter.com/surgeon_general/status/1233725785283932160 https://twitter.com/surgeon_general/status/12337257852839321...
boibombeiro 6y ago
It's seems the author didn't review previous literature on heard imunity on covid. For instance, Manaus had 76% of serumprevalence in October and the number of new cases seem stable. Fast Forward to this week, the health system collapsed, highest number of deaths in one day. https://science.sciencemag.org/content/371/6526/288 https://science.sciencemag.org/content/371/6526/288 https://www.reuters.com/article/us-health-coronavirus-brazil-amazon/brazils-amazonas-state-running-out-of-oxygen-as-covid-19-surges-idUSKBN29J2SJ https://www.reuters.com/article/us-health-coronavirus-brazil... Most (all?) highly contagious viral infection only achieve heard imunity after widespread vaccination.
- rossdavidh 6y ago
  From the Science article you refer to: "When the percentage of infected people exceeds the herd immunity threshold of 60 to 67%, or 100 × [1 – (1/R0)], each infection generates fewer than one secondary case (case reproduction number Rt < 1) and incidence declines."
  - boibombeiro 6y ago
    They used a similar reasoning as OP. The huge increase on hospitalization in this month suggests heard imunity might not be possible. Either due reinfection, either because a more agressive variant is infecting people not yet imune. Reports from region says the number of people with 40-50 years hospitalized substianlly increased when compared with first wave. This new wave of infections seems to be caused by a new variant called P1, it include both B117 (UK) and E484K (SA) mutations. This hypotesys is still under investigation, given the lack of genomic sequentialing during the first wave. Yesterday a paper on this new variant was published (and given a new name). People should be aware that is unlikely heard imunity will be achieved without vaccination. RNA virus are known to have a high mutations rate, and despite covid having a low mutation rate (given its large rna size), it still mutates a lot. And natural selection will favors the variation that spreads more.

19 points by rossdavidh 6y ago

I agree with you that most susceptible populations have probably gotten it by now, especially among people living on reservations. It's hard to imagine that the real numbers would have reached 70%, though, considering the total COVID deaths per 100k population in the Dakotas is 184 & 181 compared to New Jersey's 229, although I guess NJ does have a larger old population. I always imagine as life on the gigantic old homesteading plots to be isolated, but I have no idea.

mike_n 6y ago
it does seem very plausible that undetected cases are several times higher than confirmed/symptomatic cases. and/or, perhaps when things start to spike locally people begin to take it seriously and change their behavior a bit -- distancing/masks were not very common in the Dakotas before the post-Sturgis wave.

ineedasername 6y ago

I'm not sure they're densely populated enough to easily know which X multiplier to apply to the positive rate. People speculate infection rates as high as 10x, I would speculate that multipliers of that sort will be positively correlated with population density, meaning a lower multiplier rate and further from herd immunity.

brewdad 6y ago
I think small towns could still replicate some of the exposure risk caused by population density since there will often be only one or two stores to buy groceries, generally located in the largest town in a larger rural area. People will gather in those stores in relatively dense numbers compared to the community at large. Mix in a reluctance to wear masks and determining the correct multiplier becomes more challenging.
- ineedasername 6y ago
  Except I don't think small towns represent small-world networks: they are likely to be clustered within themselves with just a few links outside.
rossdavidh 6y ago
I absolutely believe the multiplier would be different in different places. The fact that the back-of-the-envelope calculation for the U.S. and Slovakia give similar answers, though, suggests that it may not be so different. But sure, definitely no reason to expect it so be exactly the same.

garciasn 6y ago

I appreciate the analyses but struggle with the dissemination of opinion pieces from those who do not work in public health policy or have a MD. Can someone please explain why we should give any weight to the musing of an EE software developer when this particular topic is so fraught with issue even from actual experts in the space?

reducesuffering 6y ago
Because the CDC said to not wear masks when this whole forum was citing papers and screaming that we should wear masks and wtf is the CDC doing?
- redis_mlc 6y ago
  And WHO. And Fauci. And Oxford. And usually they doubled down when it was found out they were wrong. The only person I know of who is facing any kind of accountability is Gov. Newsom, who will very likely face a recall vote over destroying the Calif. economy while taking federal funds and flouting the lockdown he himself ordered. His ambition to run for US President dims as each day goes by.
- jryb 6y ago
  The rationale that they gave at the time was that they feared people would buy up all the masks leaving hospitals undersupplied, and that people would think that wearing a mask meant that you wouldn't also need to distance yourself from others.
  - yostrovs 6y ago
    At the time, the rationale given was that masks don't work. The idea that people would go to Home Depot to buy up all the existing masks was a nonsense excuse later provided, since hospitals have their own supply mechanisms. Hoarding of toilet paper by the public did not cause a toilet paper shortage within hospitals.
  - reducesuffering 6y ago
    I'll let the US Surgeon General's words speak for themselves. Note that he has since deleted his tweet; I wonder why? "Seriously people- STOP BUYING MASKS! They are NOT effective in preventing general public from catching #Coronavirus, but if healthcare providers can't get them to care for sick patients, it puts them and our communities at risk! https://t.co/UxZRwxxKL9 https://t.co/UxZRwxxKL9" — U.S. Surgeon General (@Surgeon_General) February 29, 2020[0] Deleted tweet[1] [0]https://www.cnn.com/2020/02/29/health/face-masks-coronavirus-surgeon-general-trnd/index.html https://www.cnn.com/2020/02/29/health/face-masks-coronavirus... [1]https://twitter.com/surgeon_general/status/1233725785283932160 https://twitter.com/surgeon_general/status/12337257852839321...

boibombeiro 6y ago

It's seems the author didn't review previous literature on heard imunity on covid. For instance, Manaus had 76% of serumprevalence in October and the number of new cases seem stable. Fast Forward to this week, the health system collapsed, highest number of deaths in one day. https://science.sciencemag.org/content/371/6526/288 https://science.sciencemag.org/content/371/6526/288 https://www.reuters.com/article/us-health-coronavirus-brazil-amazon/brazils-amazonas-state-running-out-of-oxygen-as-covid-19-surges-idUSKBN29J2SJ https://www.reuters.com/article/us-health-coronavirus-brazil... Most (all?) highly contagious viral infection only achieve heard imunity after widespread vaccination.

rossdavidh 6y ago
From the Science article you refer to: "When the percentage of infected people exceeds the herd immunity threshold of 60 to 67%, or 100 × [1 – (1/R0)], each infection generates fewer than one secondary case (case reproduction number Rt < 1) and incidence declines."
- boibombeiro 6y ago
  They used a similar reasoning as OP. The huge increase on hospitalization in this month suggests heard imunity might not be possible. Either due reinfection, either because a more agressive variant is infecting people not yet imune. Reports from region says the number of people with 40-50 years hospitalized substianlly increased when compared with first wave. This new wave of infections seems to be caused by a new variant called P1, it include both B117 (UK) and E484K (SA) mutations. This hypotesys is still under investigation, given the lack of genomic sequentialing during the first wave. Yesterday a paper on this new variant was published (and given a new name). People should be aware that is unlikely heard imunity will be achieved without vaccination. RNA virus are known to have a high mutations rate, and despite covid having a low mutation rate (given its large rna size), it still mutates a lot. And natural selection will favors the variation that spreads more.