4 ms·

They're all 100% effective at stopping hospitalization/death (at least in phase 3, not necessarily out in the field). So 9% chance for any infection, but all th

They're all 100% effective at stopping hospitalization/death (at least in phase 3, not necessarily out in the field). So 9% chance for any infection, but all those that test positive have mild to no symptoms. They basically split people at a certain area into two groups, give one the real thing, another one placebo, track infections, compare the results. Comparing vaccines by effectiveness is meaningless because they're not all tested at the same place at the same time. So J&J has lower effectiveness, but it was calculated at the peak of the outbreak, when each participant interacted with Covid more frequently in their everyday lives. For the comparisons to become meaningful, it'd need to be re-done at the same place at the same urban area, with 10s of thousands of participants for each vaccine. You'd also need to have approximately similar age spread, plus similar population distribution within an urban area. Since it's all volunteer-based, this kind of study won't happen. In conclusion: take any that's available to you.

thepete2 6y ago
I really don't know why this term is thrown around in the news so much without explanation. What I thought at first (and I think is the obvious interpretation) is that with an effectiveness of 90%, 10% of vaccinated people have no protection at all.
- maxerickson 6y ago
  The companies have every incentive to publish the good results and the media doesn't care about explaining things clearly. I'm not sure I can envision a reasonable way to embargo the numbers.
- xeromal 6y ago
  Yeah, J&J especially got the shit end of the stick on that. 72% effective, in the US, at no symptoms, but 100% effective at preventing death but every talks like it's a worthless vaccine.
  - clarkevans 6y ago
    Moreover, it's only one shot. J&J is currently enrolling for a 2-shot trial (https://clinicaltrials.gov/ct2/show/NCT04614948 https://clinicaltrials.gov/ct2/show/NCT04614948), unfortunately, the control arm .. is no vaccination. I can imagine how this may hinder recruitment.
    - xeromal 6y ago
      I wonder if us legacy J&J users will be able to get a second dose at some point.
      - bluGill 6y ago
        That is the plan if it is helpful, but it depends on a lot of factors. First, of course how much better is a second shot vs one - if the difference is minimal it probably isn't worth it. I'm guessing that we will forever say the difference is too minimal - it works well enough with one shot, so why not give the second shot as a first shot to someone else? Of course this gets mixed in those who might be more vulnerable (and thus more helped with a second shot) if we can figure that out. And there is the possibility of buy a second shot for you (at double price but that isn't stated), and we send a free shot to some poor person in [pick a poor country]. There is also the question of do we reach herd immunity - if Covid isn't spreading in your country and you are not traveling to a different country where it is why make your arm sore? Probably more considerations, but the above should get you started thinking of them.
        xeromal 6y ago
        My interest is purely from avoiding further unpleasantness from catching COVID19. I took the J&J vaccine and ended up around 103F fever for a few hours so I have an inkling if I end up in the 28% who still has symptoms when catching COVID19, would I go through another bout of fevers and chills. Of course I could ride it out, but if I had the opportunity to avoid, I would!
      - antattack 6y ago
gregwebs 6y ago
The claim that they prevent death is not significantly significant. https://dalewharrison.substack.com/p/vaccine-boosterism https://dalewharrison.substack.com/p/vaccine-boosterism
- some_cut 6y ago
  This is conflating P(death|vaccinated) with P(death|infected while vaccinated).
  - stjohnswarts 6y ago
    Yeah I don't know how people miss that but I guess a lot of people read to support their opinions rather than for the truth.
ggreer 6y ago
The J&J vaccine having lower effectiveness makes sense. Unlike the mRNA vaccines which use lipid nanoparticles as their delivery mechanism, the J&J vaccine uses an adenovirus. Some fraction of the population has immunity to this adenovirus due previous exposure to similar viruses. That means the delivery mechanism won't be nearly as effective for those people. It also means that booster shots won't be nearly as effective since everyone who gets the J&J vaccine will be immune to the adenovirus. For higher booster effectiveness, they'll probably have to choose a different adenovirus. Obviously if you can get any vaccine, do so! But to claim that we can't possibly compare vaccines is silly. Yes the trials have differences, but they're not so different as to make us totally ignorant. We can use the trial data plus knowledge of the mechanism of action to make solid bets on relative effectiveness.
yumraj 6y ago
My wife and I decided to take different vaccines. I got Moderna and J&J for her, primarily as a hedge if they have different efficacy against different variants. Especially important since we have kids.
mapme 6y ago
How does rate of community spread impact efficacy calculations? The placebo and treatment group should be operating in similar areas w/ similar case rates. If there were 10,000 cases in placebo and 1,000 in vaccine, how is that different from 1,000 in placebo vs 100 in vaccine? Not read out to the same efficacy.

thepete2 6y ago

I really don't know why this term is thrown around in the news so much without explanation. What I thought at first (and I think is the obvious interpretation) is that with an effectiveness of 90%, 10% of vaccinated people have no protection at all.

maxerickson 6y ago
The companies have every incentive to publish the good results and the media doesn't care about explaining things clearly. I'm not sure I can envision a reasonable way to embargo the numbers.
xeromal 6y ago
Yeah, J&J especially got the shit end of the stick on that. 72% effective, in the US, at no symptoms, but 100% effective at preventing death but every talks like it's a worthless vaccine.
- clarkevans 6y ago
  Moreover, it's only one shot. J&J is currently enrolling for a 2-shot trial (https://clinicaltrials.gov/ct2/show/NCT04614948 https://clinicaltrials.gov/ct2/show/NCT04614948), unfortunately, the control arm .. is no vaccination. I can imagine how this may hinder recruitment.
  - xeromal 6y ago
    I wonder if us legacy J&J users will be able to get a second dose at some point.
    - bluGill 6y ago
      That is the plan if it is helpful, but it depends on a lot of factors. First, of course how much better is a second shot vs one - if the difference is minimal it probably isn't worth it. I'm guessing that we will forever say the difference is too minimal - it works well enough with one shot, so why not give the second shot as a first shot to someone else? Of course this gets mixed in those who might be more vulnerable (and thus more helped with a second shot) if we can figure that out. And there is the possibility of buy a second shot for you (at double price but that isn't stated), and we send a free shot to some poor person in [pick a poor country]. There is also the question of do we reach herd immunity - if Covid isn't spreading in your country and you are not traveling to a different country where it is why make your arm sore? Probably more considerations, but the above should get you started thinking of them.
      - xeromal 6y ago
        My interest is purely from avoiding further unpleasantness from catching COVID19. I took the J&J vaccine and ended up around 103F fever for a few hours so I have an inkling if I end up in the 28% who still has symptoms when catching COVID19, would I go through another bout of fevers and chills. Of course I could ride it out, but if I had the opportunity to avoid, I would!
    - antattack 6y ago

gregwebs 6y ago

The claim that they prevent death is not significantly significant. https://dalewharrison.substack.com/p/vaccine-boosterism https://dalewharrison.substack.com/p/vaccine-boosterism

some_cut 6y ago
This is conflating P(death|vaccinated) with P(death|infected while vaccinated).
- stjohnswarts 6y ago
  Yeah I don't know how people miss that but I guess a lot of people read to support their opinions rather than for the truth.

ggreer 6y ago

The J&J vaccine having lower effectiveness makes sense. Unlike the mRNA vaccines which use lipid nanoparticles as their delivery mechanism, the J&J vaccine uses an adenovirus. Some fraction of the population has immunity to this adenovirus due previous exposure to similar viruses. That means the delivery mechanism won't be nearly as effective for those people. It also means that booster shots won't be nearly as effective since everyone who gets the J&J vaccine will be immune to the adenovirus. For higher booster effectiveness, they'll probably have to choose a different adenovirus. Obviously if you can get any vaccine, do so! But to claim that we can't possibly compare vaccines is silly. Yes the trials have differences, but they're not so different as to make us totally ignorant. We can use the trial data plus knowledge of the mechanism of action to make solid bets on relative effectiveness.

yumraj 6y ago

My wife and I decided to take different vaccines. I got Moderna and J&J for her, primarily as a hedge if they have different efficacy against different variants. Especially important since we have kids.

mapme 6y ago

How does rate of community spread impact efficacy calculations? The placebo and treatment group should be operating in similar areas w/ similar case rates. If there were 10,000 cases in placebo and 1,000 in vaccine, how is that different from 1,000 in placebo vs 100 in vaccine? Not read out to the same efficacy.