3 ms·

[EDIT: this was written before I saw the OP's edit] There's a trial and there's real world data, and real-world data is eventually more important. Current real

by yyyk 6y ago

[EDIT: this was written before I saw the OP's edit] There's a trial and there's real world data, and real-world data is eventually more important. Current real-world data in Israel does not indicate good 1st dose efficiency [0]. It's possible the detailed release of the Clalit data [1] will change our 1st dose picture, but judging by the fact they still demand a 2 dose regiment, I suspect that Clalit data shows the same result. A theory is that the Pfizer data was accurate for the 'vanilla' virus, but 1st dose isn't enough for the B117 variant [2], and that's why the 1st dose efficiency was disappointing. [0] https://twitter.com/dvir_a/status/1359603522581454856 https://twitter.com/dvir_a/status/1359603522581454856 [1] https://www.jpost.com/health-science/clalit-data-pfizer-vaccine-reduces-risk-of-serious-covid-19-658959 https://www.jpost.com/health-science/clalit-data-pfizer-vacc... [2] https://twitter.com/AArgoetti/status/1359994165979983873 https://twitter.com/AArgoetti/status/1359994165979983873 [EDIT following OP's edit: Well, it's possible the data was misinterpreted, but there was a statistical attempt to attune for these effects, and antibody tests seem to give a plausible theory for why 1st dose was effective in trials but not real world. Even if you disagree, it's enough of a substantial objection that we can't say we know for sure 1st dose is enough.]

mlyle 6y ago
> but there was a statistical attempt to attune for these effects Can you please explain how the statistical attempt to adjust for latency of "hospitalization" at days 14-21 post-vaccination would have taken place? I believe almost all people hospitalized at days 14-21 would have been infected at times we don't expect the vaccine to be effective from the trial data-- so seeing efficacy near 0 against hospitalization at days 14-21 is indeed exactly what we'd expect. Surely if the vaccine is preventing hospitalization right after the second dose, it prevented infection some time before that, right?? Edit: Observational data is always a mess. This looks particularly bad. Efficacy is higher in the old than in the young?? This is opposite of what we saw in the RCTs. Evidence of massive betas even right after vaccination when we expect efficacy to be 0?? This effectively says the vaccinated group is nothing like the unvaccinated group.
- yyyk 6y ago
  I believe estimate of infection date is by MOH data, which tries to estimate infection date in patients by clinical data. As for other effects, the idea is to "present the full range of reasonable scenarios and show how they affect the estimation of effectiveness."[0]. I'm not saying the analysis is right (I lack the credentials to say that) but I can tell you Israeli HMOs have been disappointed by 1st dose efficiency and have been vocal about it in media. Soon there'll be a published preprint by Clalit alongside Miguel Hernán and Marc Lipsitch (so not some Israeli-only effort, there's external review), and that is likely to be definitive. For now, Clalit is keeping a 2 dose regiment and applying no pressure to change it. [0] https://twitter.com/dvir_a/status/1357653038354292737 https://twitter.com/dvir_a/status/1357653038354292737
  - mlyle 6y ago
    > I believe estimate of infection date is by MOH data, which tries to estimate infection date in patients by clinical data. I'm reading the methodology PDF and there appears to be no effort to correct for infection date. edit: Examining the MOH data-- the date of first positive test result is used for infections, and the date of hospitalization is used for hospitalization.
  - mlyle 6y ago
    Seriously.. I'm going to drop this now, but this data is a mess. The methodological assumption of inferring beta from the first few days implies, looking at the infection data, that people receiving the vaccine are significantly more careful/less susceptible to the virus than those not. But looking at hospitalization, it implies that they are WAY WAY WAY more susceptible. last edit, for real: I looked at the preliminary Cialit findings. This is much more sane: a case control study. They find benefit-- about 33% efficacy-- post day 14, unlike the data you've been showing. It's not blinded, so it is potentially wholly consistent with the Pfizer data if those vaccinated are taking 2-2.5x the risk of the control cases. To me, this seems pretty likely. And if not, it is a different subpopulation--- we don't know what the data would look like for a similar demographic in the Pfizer study. And, of course, I don't mean that we positively know that 1 dose is super effective in the real world for a longer stretch. But, it's something that's extremely likely to be shown in a blinded RCT based on the data we have so far.

by yyyk 6y ago

mlyle 6y ago

> but there was a statistical attempt to attune for these effects Can you please explain how the statistical attempt to adjust for latency of "hospitalization" at days 14-21 post-vaccination would have taken place? I believe almost all people hospitalized at days 14-21 would have been infected at times we don't expect the vaccine to be effective from the trial data-- so seeing efficacy near 0 against hospitalization at days 14-21 is indeed exactly what we'd expect. Surely if the vaccine is preventing hospitalization right after the second dose, it prevented infection some time before that, right?? Edit: Observational data is always a mess. This looks particularly bad. Efficacy is higher in the old than in the young?? This is opposite of what we saw in the RCTs. Evidence of massive betas even right after vaccination when we expect efficacy to be 0?? This effectively says the vaccinated group is nothing like the unvaccinated group.

yyyk 6y ago
I believe estimate of infection date is by MOH data, which tries to estimate infection date in patients by clinical data. As for other effects, the idea is to "present the full range of reasonable scenarios and show how they affect the estimation of effectiveness."[0]. I'm not saying the analysis is right (I lack the credentials to say that) but I can tell you Israeli HMOs have been disappointed by 1st dose efficiency and have been vocal about it in media. Soon there'll be a published preprint by Clalit alongside Miguel Hernán and Marc Lipsitch (so not some Israeli-only effort, there's external review), and that is likely to be definitive. For now, Clalit is keeping a 2 dose regiment and applying no pressure to change it. [0] https://twitter.com/dvir_a/status/1357653038354292737 https://twitter.com/dvir_a/status/1357653038354292737
- mlyle 6y ago
  > I believe estimate of infection date is by MOH data, which tries to estimate infection date in patients by clinical data. I'm reading the methodology PDF and there appears to be no effort to correct for infection date. edit: Examining the MOH data-- the date of first positive test result is used for infections, and the date of hospitalization is used for hospitalization.
- mlyle 6y ago
  Seriously.. I'm going to drop this now, but this data is a mess. The methodological assumption of inferring beta from the first few days implies, looking at the infection data, that people receiving the vaccine are significantly more careful/less susceptible to the virus than those not. But looking at hospitalization, it implies that they are WAY WAY WAY more susceptible. last edit, for real: I looked at the preliminary Cialit findings. This is much more sane: a case control study. They find benefit-- about 33% efficacy-- post day 14, unlike the data you've been showing. It's not blinded, so it is potentially wholly consistent with the Pfizer data if those vaccinated are taking 2-2.5x the risk of the control cases. To me, this seems pretty likely. And if not, it is a different subpopulation--- we don't know what the data would look like for a similar demographic in the Pfizer study. And, of course, I don't mean that we positively know that 1 dose is super effective in the real world for a longer stretch. But, it's something that's extremely likely to be shown in a blinded RCT based on the data we have so far.