4 ms·

Not concluding prior immunity but concluding that they now have immunity after having been infected. That is in progress towards herd immunity this number of pe

by erentz 7y ago

Not concluding prior immunity but concluding that they now have immunity after having been infected. That is in progress towards herd immunity this number of people actually infected being revealed by these antibody studies is what is interesting. And based on my hacky heuristic described above that is currently around 2.6%. So we are still a long way off herd immunity. But at the same time closer than we thought we were.

ignoramous 7y ago
> So we are still a long way off herd immunity. But at the same time closer than we thought we were. Yes and no. A disease is endemic when R0 x S = 1 [0]. R0 for SARS-CoV-2 is estimated to be 2.5 to 3.5 and some models predicting a much higher 5.7 [1]. The herd immunity threshold is given by (1 - S)%, which implies when R0 = 2.5, 60% of the population would need to be immune; similarly 71.42% and 82.45% for R0s, 3.5 and 5.7, respectively. [0] https://en.wikipedia.org/wiki/Endemic_(epidemiology) https://en.wikipedia.org/wiki/Endemic_(epidemiology) [1] https://news.ycombinator.com/item?id=22817942 https://news.ycombinator.com/item?id=22817942
- fiftyfifty 7y ago
  What percentage of immunity can we expect to see a slowdown in the spread of the disease? While we may need 60% or more to achieve full herd immunity surely somewhere lower than that we can expect to see a noticeable reduction in the spread?
  - ignoramous 7y ago
    > ...noticeable reduction in the spread? I believe the SIR model [0] answers those questions. 3blue1brown's video on the topic is super digestible and informative [1]. In short, the discovery of a prophylactic if not a therapeutic treatment are our best immediate bets, absent which, quarantines and lockdowns will have to persist to curb the spread of a disease as infectious as covid-19 whilst we patiently wait for an effective vaccine against it [2]. [0] https://en.wikipedia.org/wiki/Compartmental_models_in_epidemiology#The_SIR_model https://en.wikipedia.org/wiki/Compartmental_models_in_epidem... [1] https://www.youtube.com/watch?v=gxAaO2rsdIs https://www.youtube.com/watch?v=gxAaO2rsdIs [2] https://en.wikipedia.org/wiki/Vaccine_efficacy https://en.wikipedia.org/wiki/Vaccine_efficacy

by erentz 7y ago

ignoramous 7y ago

> So we are still a long way off herd immunity. But at the same time closer than we thought we were. Yes and no. A disease is endemic when R0 x S = 1 [0]. R0 for SARS-CoV-2 is estimated to be 2.5 to 3.5 and some models predicting a much higher 5.7 [1]. The herd immunity threshold is given by (1 - S)%, which implies when R0 = 2.5, 60% of the population would need to be immune; similarly 71.42% and 82.45% for R0s, 3.5 and 5.7, respectively. [0] https://en.wikipedia.org/wiki/Endemic_(epidemiology) https://en.wikipedia.org/wiki/Endemic_(epidemiology) [1] https://news.ycombinator.com/item?id=22817942 https://news.ycombinator.com/item?id=22817942

fiftyfifty 7y ago
What percentage of immunity can we expect to see a slowdown in the spread of the disease? While we may need 60% or more to achieve full herd immunity surely somewhere lower than that we can expect to see a noticeable reduction in the spread?
- ignoramous 7y ago
  > ...noticeable reduction in the spread? I believe the SIR model [0] answers those questions. 3blue1brown's video on the topic is super digestible and informative [1]. In short, the discovery of a prophylactic if not a therapeutic treatment are our best immediate bets, absent which, quarantines and lockdowns will have to persist to curb the spread of a disease as infectious as covid-19 whilst we patiently wait for an effective vaccine against it [2]. [0] https://en.wikipedia.org/wiki/Compartmental_models_in_epidemiology#The_SIR_model https://en.wikipedia.org/wiki/Compartmental_models_in_epidem... [1] https://www.youtube.com/watch?v=gxAaO2rsdIs https://www.youtube.com/watch?v=gxAaO2rsdIs [2] https://en.wikipedia.org/wiki/Vaccine_efficacy https://en.wikipedia.org/wiki/Vaccine_efficacy