4 ms·

Isn't this hypothesis pretty easy to validate/falsify? Just take a random sample of 1K NY residents and test them for antibody/t-cell presence. 1K is plenty t

Isn't this hypothesis pretty easy to validate/falsify? Just take a random sample of 1K NY residents and test them for antibody/t-cell presence. 1K is plenty to make a statistically significant sample size when you're suggesting the true infection rate is double digits. Why do we NOT know what the population infection rate is? It seems relatively easy to do.

gloriosoc 6y ago
I have some ideas about why the last released Antibody data from NYC was in mid April. I'm pretty sure it's to do with politics and not science. Herd immunity is a bad look for a politician. But that is pure speculation.
- smallgovt 6y ago
  That crossed my mind as well, but if this were the case, surely a member of the opposing party would fund such a study. Given that this also hasn't happened, I wonder if there's another reason. Is it not as simple as paying 1K random ppl $100 to come in and take a test?
  - gloriosoc 6y ago
    Oh wait here we go- New York just released its antibody data. I just saw this when googling https://www.nytimes.com/2020/08/19/nyregion/new-york-city-antibody-test.html https://www.nytimes.com/2020/08/19/nyregion/new-york-city-an...
gloriosoc 6y ago
But we also don't know what antibody/T-cell levels, which btw testing for Tcells is not widely available or commercial, would = herd immunity. So there is no result that would prove herd immunity.
- smallgovt 6y ago
  > But we also don't know what antibody/T-cell levels... would = herd immunity. OK, but wouldn't a random sampling at least provide an answer to what pct of the population was infected at some point? That seems like a great starting point.
  - gloriosoc 6y ago
    Yes, and for some reason, NYC and the CDC are not releasing results later than mid April. It is very suspicious imo. They were releasing antibody results and then abruptly stopped without explanation.
    - smallgovt 6y ago
      Can you point me to the latest released results? Thanks!
      - gloriosoc 6y ago
        This just came out https://www1.nyc.gov/site/doh/covid/covid-19-data-testing.page https://www1.nyc.gov/site/doh/covid/covid-19-data-testing.pa...
        smallgovt 6y ago
        The antibody test results for this data set don't seem representative of the population at large. Reason being, if you look at the antibody positivity rate, it consistently drops as time goes on (whereas everything I've read suggests it should increase with time as more ppl have been infected). My guess is that at the beginning, hospitals were only testing COVID-sick patients, and as time went on testing became more widespread.
        gloriosoc 6y ago
        Or the initial antibodies drop in people that have had COVID over time (which they probably do). The antibody tests test for the kind of antibodies that are present immediately- over time a previously infected person will have less of those antibodies and more of the back up Tcell kind. You can read a review on this here: https://www.nature.com/articles/d41586-020-02400-7 https://www.nature.com/articles/d41586-020-02400-7.
tghw 6y ago
Seroprevalence studies[1] in Italy, France, and Spain indicated we were a very long way off form herd immunity. They were in the range of 11-15%, where herd immunity would only start kicking in at about 70%. Based on cases per capita, the US might be 2-3 times higher than western Europe, but not yet at 70%. I think the flaw in the piece is the author greatly underestimates the impact of the drastic measures we've taken to get those trends down. A lot of people are working from home, kids largely aren't back in school, and many of our other contact points outside of our households have been modified to minimize the risk of transmission. Seeing what happened to Israel when they reopened schools does not bode well for the US. [2] Edit: NYC had ~20% prevalence in mid-June [3], after they had come back down from their peak. They've had many more cases per capita than anywhere else in the US, but their new cases have been flat since then, meaning prevalence has not increased significantly. Prevalence elsewhere in the US is likely in the 5-10% range. [1] https://www.sciencedirect.com/science/article/pii/S0048969720323342 https://www.sciencedirect.com/science/article/pii/S004896972... [2] https://pbs.twimg.com/media/Ees8MesX0AAbDE2?format=png&name=900x900 https://pbs.twimg.com/media/Ees8MesX0AAbDE2?format=png&name=... https://www.wsj.com/articles/israelis-fear-schools-reopened-too-soon-as-covid-19-cases-climb-11594760001 https://www.wsj.com/articles/israelis-fear-schools-reopened-... [3] https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/commercial-lab-surveys.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/comm...
asdff 6y ago
How are you sampling people? Unless you track people down and knock on doors and have them submit a sample right there, it won't be random, but a subset of people willing to take time out of their life to participate in a research study.

gloriosoc 6y ago

I have some ideas about why the last released Antibody data from NYC was in mid April. I'm pretty sure it's to do with politics and not science. Herd immunity is a bad look for a politician. But that is pure speculation.

smallgovt 6y ago
That crossed my mind as well, but if this were the case, surely a member of the opposing party would fund such a study. Given that this also hasn't happened, I wonder if there's another reason. Is it not as simple as paying 1K random ppl $100 to come in and take a test?
- gloriosoc 6y ago
  Oh wait here we go- New York just released its antibody data. I just saw this when googling https://www.nytimes.com/2020/08/19/nyregion/new-york-city-antibody-test.html https://www.nytimes.com/2020/08/19/nyregion/new-york-city-an...

gloriosoc 6y ago

But we also don't know what antibody/T-cell levels, which btw testing for Tcells is not widely available or commercial, would = herd immunity. So there is no result that would prove herd immunity.

smallgovt 6y ago
> But we also don't know what antibody/T-cell levels... would = herd immunity. OK, but wouldn't a random sampling at least provide an answer to what pct of the population was infected at some point? That seems like a great starting point.
- gloriosoc 6y ago
  Yes, and for some reason, NYC and the CDC are not releasing results later than mid April. It is very suspicious imo. They were releasing antibody results and then abruptly stopped without explanation.
  - smallgovt 6y ago
    Can you point me to the latest released results? Thanks!
    - gloriosoc 6y ago
      This just came out https://www1.nyc.gov/site/doh/covid/covid-19-data-testing.page https://www1.nyc.gov/site/doh/covid/covid-19-data-testing.pa...
      - smallgovt 6y ago
        The antibody test results for this data set don't seem representative of the population at large. Reason being, if you look at the antibody positivity rate, it consistently drops as time goes on (whereas everything I've read suggests it should increase with time as more ppl have been infected). My guess is that at the beginning, hospitals were only testing COVID-sick patients, and as time went on testing became more widespread.
        gloriosoc 6y ago
        Or the initial antibodies drop in people that have had COVID over time (which they probably do). The antibody tests test for the kind of antibodies that are present immediately- over time a previously infected person will have less of those antibodies and more of the back up Tcell kind. You can read a review on this here: https://www.nature.com/articles/d41586-020-02400-7 https://www.nature.com/articles/d41586-020-02400-7.

tghw 6y ago

Seroprevalence studies[1] in Italy, France, and Spain indicated we were a very long way off form herd immunity. They were in the range of 11-15%, where herd immunity would only start kicking in at about 70%. Based on cases per capita, the US might be 2-3 times higher than western Europe, but not yet at 70%. I think the flaw in the piece is the author greatly underestimates the impact of the drastic measures we've taken to get those trends down. A lot of people are working from home, kids largely aren't back in school, and many of our other contact points outside of our households have been modified to minimize the risk of transmission. Seeing what happened to Israel when they reopened schools does not bode well for the US. [2] Edit: NYC had ~20% prevalence in mid-June [3], after they had come back down from their peak. They've had many more cases per capita than anywhere else in the US, but their new cases have been flat since then, meaning prevalence has not increased significantly. Prevalence elsewhere in the US is likely in the 5-10% range. [1] https://www.sciencedirect.com/science/article/pii/S0048969720323342 https://www.sciencedirect.com/science/article/pii/S004896972... [2] https://pbs.twimg.com/media/Ees8MesX0AAbDE2?format=png&name=900x900 https://pbs.twimg.com/media/Ees8MesX0AAbDE2?format=png&name=... https://www.wsj.com/articles/israelis-fear-schools-reopened-too-soon-as-covid-19-cases-climb-11594760001 https://www.wsj.com/articles/israelis-fear-schools-reopened-... [3] https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/commercial-lab-surveys.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/comm...

asdff 6y ago

How are you sampling people? Unless you track people down and knock on doors and have them submit a sample right there, it won't be random, but a subset of people willing to take time out of their life to participate in a research study.