4 ms·

One thing to note is that the effectiveness metric also includes the behavioral and populational differences. I'd personally really like to know what the metri

One thing to note is that the effectiveness metric also includes the behavioral and populational differences. I'd personally really like to know what the metric would be if (hypothetically, just for analysis) the vaccine was a placebo. For example, if the people who get the vaccine are generally more able to work from home, then the metric would still be significantly above zero. Just for clarity, I believe that the vaccine is effective, but I question the measurement methodology.

awb 5y ago
We’ll have to think of a different methodology because it’s not ethical to issue placebo vaccines during a pandemic.
- FabHK 5y ago
  Well, antivaxxers would take the placebo. But they wouldn't take the vaccine. So you can't randomise the trial.
  - FabHK 5y ago
    I was serious with that comment. You can do longitudinal studies now, and people do, comparing infection/hospitalisation/death rates among vaccinated and unvaccinated people. But those have very serious confounders, namely that those who are still unvaccinated might behave rather different from everyone else. To overcome this, you'd need an RCT. But you're unlikely to find either a) unvaccinated people that want to be vaccinated, yet would be ok to get a placebo instead, or b) unvaccinated people that don't want to be vaccinated yet would be ok to get a vaccination instead.
    - awb 5y ago
      Agreed, not sure why you were downvoted.
FabHK 5y ago
Well, one important confounder is age (older people tend to be more vaccinated), but they control for that. Many other confounders cannot easily be controlled for, but is there any reason to assume that they're correlated with the outcome? It could be that vaccinated people are more careful in terms of meeting other people. At any rate, we had big RCTs at the beginning that demonstrated efficacy against the then prevailing variant (alpha, I assume). It'll be tricky to repeat an RCT at this stage.
- dehrmann 5y ago
  Another big confounder is household size.
smorgusofborg 5y ago
I don't really get the example of being able to work from home, but I would expect differences are extremely regional/national. In some countries there's a formal labor law for doctors notes after X days that is known by all and which might mean your doctor checks and registers the case(?) in other places it is total discretion if a manager demands a note but rarely does in places that aren't shift work oriented.
- Scene_Cast2 5y ago
  With the WFH example - suppose that 1) WFH is issued by companies as a blanket policy (different from 2-week isolation from getting sick) 2) people who get the vaccine tend to be the ones that WFH, and 3) WFH allows for less exposure. In that case, the people who get the vaccine tend to have less exposure and fewer chances to get sick, regardless of vaccine efficacy.
  - smorgusofborg 5y ago
    There's definite vaccine rate differences in industries, but much of that might be largely explained by age demographics of industries.. Given two people who WFH the vaccinated one can conveniently eat in a restaurant and go to the gym while the unvaccinated needs to get take out or is getting regular tests. I think vaccinated people have much more interaction with the virus unmasked in an indoor environment but much less likelihood of ever being tested when having light or no symptoms.
- rsynnott 5y ago
  > I don't really get the example of being able to work from home, but I would expect differences are extremely regional/national. In some countries (the US is an example); there's a social class aspect to vaccination; highly educated people are more likely to be vaccinated, and also more likely to work from home. However, if this was a big factor you'd expect vaccines to appear dramatically less effective in near-universal-vaccination countries, like Portugal. That doesn't seem to be the case.

awb 5y ago

We’ll have to think of a different methodology because it’s not ethical to issue placebo vaccines during a pandemic.

FabHK 5y ago
Well, antivaxxers would take the placebo. But they wouldn't take the vaccine. So you can't randomise the trial.
- FabHK 5y ago
  I was serious with that comment. You can do longitudinal studies now, and people do, comparing infection/hospitalisation/death rates among vaccinated and unvaccinated people. But those have very serious confounders, namely that those who are still unvaccinated might behave rather different from everyone else. To overcome this, you'd need an RCT. But you're unlikely to find either a) unvaccinated people that want to be vaccinated, yet would be ok to get a placebo instead, or b) unvaccinated people that don't want to be vaccinated yet would be ok to get a vaccination instead.
  - awb 5y ago
    Agreed, not sure why you were downvoted.

FabHK 5y ago

Well, one important confounder is age (older people tend to be more vaccinated), but they control for that. Many other confounders cannot easily be controlled for, but is there any reason to assume that they're correlated with the outcome? It could be that vaccinated people are more careful in terms of meeting other people. At any rate, we had big RCTs at the beginning that demonstrated efficacy against the then prevailing variant (alpha, I assume). It'll be tricky to repeat an RCT at this stage.

dehrmann 5y ago
Another big confounder is household size.

smorgusofborg 5y ago

I don't really get the example of being able to work from home, but I would expect differences are extremely regional/national. In some countries there's a formal labor law for doctors notes after X days that is known by all and which might mean your doctor checks and registers the case(?) in other places it is total discretion if a manager demands a note but rarely does in places that aren't shift work oriented.

Scene_Cast2 5y ago
With the WFH example - suppose that 1) WFH is issued by companies as a blanket policy (different from 2-week isolation from getting sick) 2) people who get the vaccine tend to be the ones that WFH, and 3) WFH allows for less exposure. In that case, the people who get the vaccine tend to have less exposure and fewer chances to get sick, regardless of vaccine efficacy.
- smorgusofborg 5y ago
  There's definite vaccine rate differences in industries, but much of that might be largely explained by age demographics of industries.. Given two people who WFH the vaccinated one can conveniently eat in a restaurant and go to the gym while the unvaccinated needs to get take out or is getting regular tests. I think vaccinated people have much more interaction with the virus unmasked in an indoor environment but much less likelihood of ever being tested when having light or no symptoms.
rsynnott 5y ago
> I don't really get the example of being able to work from home, but I would expect differences are extremely regional/national. In some countries (the US is an example); there's a social class aspect to vaccination; highly educated people are more likely to be vaccinated, and also more likely to work from home. However, if this was a big factor you'd expect vaccines to appear dramatically less effective in near-universal-vaccination countries, like Portugal. That doesn't seem to be the case.