6 ms·

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

by 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.
  - mlyle 6y ago
    > but there are also plenty of ways bias can creep into an RCT. Yes, but in this case generally in the direction towards less efficacy too. People are unblinded inadvertently by their side effects and then act more recklessly, etc. And this is immaterial: yes, RCTs can be fucked up, but CCTs are almost always fucked up. > 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. It could be. Anything could be. The question is the likelihood. But the other source arguing negative efficacy when even shitty case control data is showing positive efficacy is a little dubious. Indeed, the hwole core assumption on that time series data is so bad-- assuming that people will behave the same from days 0-7 and from 7 on, when they've been cautioned that the vaccine is not immediately effective... Seriously, smh. > Can decision makers really take that risk? To do what I suggested? Yes. I suggested to run a trial. Don't pretend that I suggested anything different to strengthen your case. It's a trial exceptionally likely to yield positive results for delaying the second dose.
    - yyyk 6y ago
      [EDIT: Removed an irrelevant paragraph.] There were suggestions earlier that 1st dose was "for sure" more effective, and judging by UK response some countries are desperate enough to try this without a trial. You didn't mean it, but it's possible some places will go for it. I'm just asking people to look before they leap, it's not a sure thing. >Indeed, the whole core assumption on that time series data is so bad-- assuming that people will behave the same from days 0-7 and from 7 on, when they've been cautioned that the vaccine is not immediately effective... Seriously, smh. Well, according to his github explanation[0] there was an attempt to account for that: "It is assumed that on the days following the vaccination, there is increased caution to avoid social encounters." [0] https://github.com/dviraran/covid_analyses https://github.com/dviraran/covid_analyses
      - mlyle 6y ago
        Well, you're trying my patience by putting words in my mouth that I didn't say: I didn't suggest decisionmakers immediately give everyone one dose. Are you making a dishonest argument, or did you just fail to read what I originally said. Your assertions are hard to reconcile with e.g. https://pbs.twimg.com/media/Et4moRCXAAAZ18o?format=jpg&name=large https://pbs.twimg.com/media/Et4moRCXAAAZ18o?format=jpg&name=... Note that most of the people positive at 21-27 days would have been exposed before the 2nd dose... Yes, it's crappy time series data, but...

by yyyk 6y ago

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.
- mlyle 6y ago
  > but there are also plenty of ways bias can creep into an RCT. Yes, but in this case generally in the direction towards less efficacy too. People are unblinded inadvertently by their side effects and then act more recklessly, etc. And this is immaterial: yes, RCTs can be fucked up, but CCTs are almost always fucked up. > 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. It could be. Anything could be. The question is the likelihood. But the other source arguing negative efficacy when even shitty case control data is showing positive efficacy is a little dubious. Indeed, the hwole core assumption on that time series data is so bad-- assuming that people will behave the same from days 0-7 and from 7 on, when they've been cautioned that the vaccine is not immediately effective... Seriously, smh. > Can decision makers really take that risk? To do what I suggested? Yes. I suggested to run a trial. Don't pretend that I suggested anything different to strengthen your case. It's a trial exceptionally likely to yield positive results for delaying the second dose.
  - yyyk 6y ago
    [EDIT: Removed an irrelevant paragraph.] There were suggestions earlier that 1st dose was "for sure" more effective, and judging by UK response some countries are desperate enough to try this without a trial. You didn't mean it, but it's possible some places will go for it. I'm just asking people to look before they leap, it's not a sure thing. >Indeed, the whole core assumption on that time series data is so bad-- assuming that people will behave the same from days 0-7 and from 7 on, when they've been cautioned that the vaccine is not immediately effective... Seriously, smh. Well, according to his github explanation[0] there was an attempt to account for that: "It is assumed that on the days following the vaccination, there is increased caution to avoid social encounters." [0] https://github.com/dviraran/covid_analyses https://github.com/dviraran/covid_analyses
    - mlyle 6y ago
      Well, you're trying my patience by putting words in my mouth that I didn't say: I didn't suggest decisionmakers immediately give everyone one dose. Are you making a dishonest argument, or did you just fail to read what I originally said. Your assertions are hard to reconcile with e.g. https://pbs.twimg.com/media/Et4moRCXAAAZ18o?format=jpg&name=large https://pbs.twimg.com/media/Et4moRCXAAAZ18o?format=jpg&name=... Note that most of the people positive at 21-27 days would have been exposed before the 2nd dose... Yes, it's crappy time series data, but...