3 ms·

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 "

by 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.
- yyyk 6y ago
  I lack the ability to defend that analysis, but as I mentioned, it's not the only analysis showing reduced 1st dose efficiency. AFAICT, there's a consensus with Israeli HMO researches it's not as good as the Pfizer trials. >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. I suspect you're talking about a different analysis then the preprint I'm talking about. IIRC, the preliminary analysis you're talking about was released earlier and without external verification. Anyway, I don't see how your criteria can be falsified. If the data were to show 16% 1st dose efficiency, it would have been possible to claim the vaccinated are taking 4-5x risk. But how can you separate that from the possibility 1st dose is 4-5x less efficient than in the trials? Same thing for the reported 33% efficiency, it could be vaccinated are merely 1.25x less careful. If so, there's a reasonable chance 1st dose isn't enough for Pfizer and by implication Moderna.
  - mlyle 6y ago
    > Anyway, I don't see how your criteria can be falsified. If the data were to show 16% 1st dose efficiency, it can be claimed the vaccinated are taking 4-5x risk. But how can you separate that from the 1st dose being 4-5x less efficient than in the trials? It can't be. This is why you can't really trust case control trials, especially when the participants are likely to behave differently between the groups. This is why, if you have a choice between a CCT and a RCT, you take the RCT data. And we have a RCT, so... And the difference between the RCT and CCT is in the direction we'd expect... and the magnitude isn't crazy high, so... edit: and now you're editing under me. ;)
    - yyyk 6y ago
      Yes, but there are also plenty of ways bias can creep into an RCT. Also remember we're not talking about the same virus - the trials were on 'vanilla' virus while by the time Pfizer arrived to Israel en mass B117 was prevalent. It could be the 1st dose is less efficient with B117. That's close to what the other link I provided earlier[0] argued. Can decision makers really take that risk? [0] https://www.researchsquare.com/article/rs-226857/v1 https://www.researchsquare.com/article/rs-226857/v1 Earlier I linked to a short twitter thread explaining the article.

by yyyk 6y ago

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.

yyyk 6y ago
I lack the ability to defend that analysis, but as I mentioned, it's not the only analysis showing reduced 1st dose efficiency. AFAICT, there's a consensus with Israeli HMO researches it's not as good as the Pfizer trials. >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. I suspect you're talking about a different analysis then the preprint I'm talking about. IIRC, the preliminary analysis you're talking about was released earlier and without external verification. Anyway, I don't see how your criteria can be falsified. If the data were to show 16% 1st dose efficiency, it would have been possible to claim the vaccinated are taking 4-5x risk. But how can you separate that from the possibility 1st dose is 4-5x less efficient than in the trials? Same thing for the reported 33% efficiency, it could be vaccinated are merely 1.25x less careful. If so, there's a reasonable chance 1st dose isn't enough for Pfizer and by implication Moderna.
- mlyle 6y ago
  > Anyway, I don't see how your criteria can be falsified. If the data were to show 16% 1st dose efficiency, it can be claimed the vaccinated are taking 4-5x risk. But how can you separate that from the 1st dose being 4-5x less efficient than in the trials? It can't be. This is why you can't really trust case control trials, especially when the participants are likely to behave differently between the groups. This is why, if you have a choice between a CCT and a RCT, you take the RCT data. And we have a RCT, so... And the difference between the RCT and CCT is in the direction we'd expect... and the magnitude isn't crazy high, so... edit: and now you're editing under me. ;)
  - yyyk 6y ago
    Yes, but there are also plenty of ways bias can creep into an RCT. Also remember we're not talking about the same virus - the trials were on 'vanilla' virus while by the time Pfizer arrived to Israel en mass B117 was prevalent. It could be the 1st dose is less efficient with B117. That's close to what the other link I provided earlier[0] argued. Can decision makers really take that risk? [0] https://www.researchsquare.com/article/rs-226857/v1 https://www.researchsquare.com/article/rs-226857/v1 Earlier I linked to a short twitter thread explaining the article.