24 ms·

TL;DR: You are correct! The counter-story seems to be based on radically misreading data out of Israel, which seems to show higher infection rates among the va

TL;DR: You are correct! The counter-story seems to be based on radically misreading data out of Israel, which seems to show higher infection rates among the vaccinated, a reading which fails to take into account the incredibly high rate of vaccination there. So yeah, there are more infections among the 78% vaccinated than among the 22% unvaccinated. Given that there are 3.5x as many people in the first group, that's not entirely unexpected. As a percentage of the population, the vaccinated are still less likely to get infected, and less likely to deal with severe consequences.

angelzen 5y ago
CDC says vaccines are only 66 percent effective at preventing Delta infection. As far as I can understand, this means 34% of vaccinated people develop a covid infection. I'm having a hard time squaring this with 'vaccines prevent infection' thesis. Perhaps I'm missing something obvious? (Yes, I'm aware the fraction is better against severe Delta infection. Yes, I agree 3x reduction is infection rate is a good thing.) https://www.webmd.com/vaccines/covid-19-vaccine/news/20210825/cdc-covid-19-vaccines-66-percent-effective-against-delta-variant https://www.webmd.com/vaccines/covid-19-vaccine/news/2021082...
- lamontcg 5y ago
  > CDC says vaccines are only 66 percent effective at preventing Delta infection WITH A 95% CONFIDENCE INTERVAL OF 26% TO 84% They only statistically modeled how much their unvaccinated population was already recovered from coronavirus based on estimates of community spread, among other issues with that number. https://www.cdc.gov/mmwr/volumes/70/wr/mm7034e4.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7034e4.htm And when you have a CI of something like that size, of course you wind up in the middle of it -- the actual value could very well be closer to 80% due to systematic uncertainties in the modeling.
  - disgruntledphd2 5y ago
    Or 30%, to be fair.
    - lamontcg 5y ago
      published on the CDC site today: 77% (74%-80%) VE for pfizer and 92% (89%-93%) VE for moderna. With only some evidence of reduced VE against delta and/or waning in those > 75 years old: https://www.cdc.gov/mmwr/volumes/70/wr/mm7037e2.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7037e2.htm
      - disgruntledphd2 5y ago
        That's a very reassuring result, thanks for sharing. Interesting that moderna continues to do better, and looking forward to seeing the studies VE versus time since vaccination.
- MatteoFrigo 5y ago
  > this means 34% of vaccinated people develop a covid infection That's not what "effective" means. It means that if your probability of getting infected without the vaccine is p, your probability of getting infected with the vaccine is .34*p. One way to think about it is that the "ineffectiveness" is the relative risk P[infected|vaccinated]/P[infected|unvaccinated], and effectiveness is 1-ineffectiveness. A vaccine can be 100% effective even if P[infected] is negligible. P[infected] is per unit time and does not account for the dynamics of the situation. For example, if the vaccine is not powerful enough to make R<1, then everybody becomes infected eventually regardless of the vaccine.
  - angelzen 5y ago
    Thanks!
voiper1 5y ago
Israel is showing per-capita rates by default.. in some of the data... on https://datadashboard.health.gov.il/COVID-19/ https://datadashboard.health.gov.il/COVID-19/ to avoid this issue: e.g. hospitalized above age 60 (חולים קשה - התחסנות) 162/100,000 unvaccinated 40/100,000 2 dose (I think) 5/100,000 2 dose + booster If you'd just look at the raw numbers, the vaccine doesn't appear so helpful: 226 unvaccinated, 116 with 2 doses, 55 with 3 doses. Looks like it barely helps.
- angelzen 5y ago
  There is also rate data from UK on covid delta (week 32-35 2021), breakdown by vax status & age, see Figure 2a. Cases under 40 is 1/2 vax/unvax, cases over 40 is actually slightly larger for vax than unvax. I had a sense vaccines are not perfect wrt infection, but didn't expect actual numbers to be that close. Fortunately vaccines are very still very good at preventing severe cases (hospitaliations), see Figure 2d. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1016465/Vaccine_surveillance_report_-_week_36.pdf https://assets.publishing.service.gov.uk/government/uploads/...
  - kcplate 5y ago
    Preventing severe cases really only benefit the vaccinated and perhaps medical providers. It’s a lousy justification for a mandate that forces someone to do something that cannot be undone.
  - MatteoFrigo 5y ago
    Great document, thanks for the link. The document says that >97% of the blood-donor population in the UK has some kind of antibodies, either from natural infection or vaccines. This seems like an astonishingly high number.

angelzen 5y ago

CDC says vaccines are only 66 percent effective at preventing Delta infection. As far as I can understand, this means 34% of vaccinated people develop a covid infection. I'm having a hard time squaring this with 'vaccines prevent infection' thesis. Perhaps I'm missing something obvious? (Yes, I'm aware the fraction is better against severe Delta infection. Yes, I agree 3x reduction is infection rate is a good thing.) https://www.webmd.com/vaccines/covid-19-vaccine/news/20210825/cdc-covid-19-vaccines-66-percent-effective-against-delta-variant https://www.webmd.com/vaccines/covid-19-vaccine/news/2021082...

lamontcg 5y ago
> CDC says vaccines are only 66 percent effective at preventing Delta infection WITH A 95% CONFIDENCE INTERVAL OF 26% TO 84% They only statistically modeled how much their unvaccinated population was already recovered from coronavirus based on estimates of community spread, among other issues with that number. https://www.cdc.gov/mmwr/volumes/70/wr/mm7034e4.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7034e4.htm And when you have a CI of something like that size, of course you wind up in the middle of it -- the actual value could very well be closer to 80% due to systematic uncertainties in the modeling.
- disgruntledphd2 5y ago
  Or 30%, to be fair.
  - lamontcg 5y ago
    published on the CDC site today: 77% (74%-80%) VE for pfizer and 92% (89%-93%) VE for moderna. With only some evidence of reduced VE against delta and/or waning in those > 75 years old: https://www.cdc.gov/mmwr/volumes/70/wr/mm7037e2.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7037e2.htm
    - disgruntledphd2 5y ago
      That's a very reassuring result, thanks for sharing. Interesting that moderna continues to do better, and looking forward to seeing the studies VE versus time since vaccination.
MatteoFrigo 5y ago
> this means 34% of vaccinated people develop a covid infection That's not what "effective" means. It means that if your probability of getting infected without the vaccine is p, your probability of getting infected with the vaccine is .34*p. One way to think about it is that the "ineffectiveness" is the relative risk P[infected|vaccinated]/P[infected|unvaccinated], and effectiveness is 1-ineffectiveness. A vaccine can be 100% effective even if P[infected] is negligible. P[infected] is per unit time and does not account for the dynamics of the situation. For example, if the vaccine is not powerful enough to make R<1, then everybody becomes infected eventually regardless of the vaccine.
- angelzen 5y ago
  Thanks!

voiper1 5y ago

Israel is showing per-capita rates by default.. in some of the data... on https://datadashboard.health.gov.il/COVID-19/ https://datadashboard.health.gov.il/COVID-19/ to avoid this issue: e.g. hospitalized above age 60 (חולים קשה - התחסנות) 162/100,000 unvaccinated 40/100,000 2 dose (I think) 5/100,000 2 dose + booster If you'd just look at the raw numbers, the vaccine doesn't appear so helpful: 226 unvaccinated, 116 with 2 doses, 55 with 3 doses. Looks like it barely helps.

angelzen 5y ago
There is also rate data from UK on covid delta (week 32-35 2021), breakdown by vax status & age, see Figure 2a. Cases under 40 is 1/2 vax/unvax, cases over 40 is actually slightly larger for vax than unvax. I had a sense vaccines are not perfect wrt infection, but didn't expect actual numbers to be that close. Fortunately vaccines are very still very good at preventing severe cases (hospitaliations), see Figure 2d. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1016465/Vaccine_surveillance_report_-_week_36.pdf https://assets.publishing.service.gov.uk/government/uploads/...
- kcplate 5y ago
  Preventing severe cases really only benefit the vaccinated and perhaps medical providers. It’s a lousy justification for a mandate that forces someone to do something that cannot be undone.
- MatteoFrigo 5y ago
  Great document, thanks for the link. The document says that >97% of the blood-donor population in the UK has some kind of antibodies, either from natural infection or vaccines. This seems like an astonishingly high number.