4 ms·

I find the Johnson and Johnson Press Release [1] more informative. It gives a lot more detail on the study, including linking to their protocol [2]. It’s unfor

by boulos 6y ago

I find the Johnson and Johnson Press Release [1] more informative. It gives a lot more detail on the study, including linking to their protocol [2]. It’s unfortunate, but the different vaccine trials all have different demographics and different measures of efficacy. IIRC, the Moderna “95%” is not “only 5% developed COVID” but rather “95% didn’t end up showing any symptoms” while AstraZeneca was doing weekly testing (again this is from memory). With so many people being asymptomatic, the difference between “95%” and “66%” is in the details (which is definitely why Johnson and Johnson also highlight their 72% in the US, and 85% against hospitalization/death). tl;dr: each vaccine group made reasonable, independent choices for their effectiveness metrics, but they’re not the same metric. [1] https://www.jnj.com/johnson-johnson-announces-single-shot-janssen-covid-19-vaccine-candidate-met-primary-endpoints-in-interim-analysis-of-its-phase-3-ensemble-trial https://www.jnj.com/johnson-johnson-announces-single-shot-ja... [2] https://www.jnj.com/coronavirus/covid-19-phase-3-study-clinical-protocol https://www.jnj.com/coronavirus/covid-19-phase-3-study-clini...

xiphias2 6y ago
Also the results of this vaccine isn't that difference from just using 1 shot of another vaccine. It looks like as long as it's safe to do it, the 2nd shot is worth it.
m-ee 6y ago
They do not have different measures of eficacy. AZ did more testing to look at symptomatic infections but that was not used in the primary efficacy calculation. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32661-1/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
- boulos 6y ago
  I believe AZ was doing weekly testing while Moderna (maybe?) was doing “test if symptomatic”. That’s a huge difference.
  - m-ee 6y ago
    If they didn't have symptoms, they weren't counted in the headline efficacy numbers we're talking about. "The primary outcome was virologically confirmed, symptomatic COVID-19, defined as a NAAT-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia)."
- mlyle 6y ago
  Just a nit: they don't have exactly the same outcome measure, definition of "severe", "symptomatic", etc. Nor were they conducted in the same, time, or the exactly same demographics. Nor did they use the same protocol: testing weekly with a swab and detecting and informing the participant of a positive status will get that person to report symptoms to the trial more often than if you don't. They use similar measures of efficacy but they're not the same thing and are not perfectly comparable. Still, it seems very likely that the mRNA vaccines are much better than AZ.
  - m-ee 6y ago
    You’re absolutely right, but I didn’t want the overall message to get lost in the details. I’ve been seeing people parrot the “AZ is actually much better than it looks because they included asymptomatic patients” for months now and it’s just incorrect.
    - boulos 6y ago
      I’m honestly confused! Can you point me to your source for the excerpts in your sibling comments? Edit: reading your lancet link now (sorry about that). My understanding from reading the description of the Moderna results was “XX / YYY people developed covid; but we didn’t test everyone in the YYY set” (so people who definitely got it / went to a hospital / whatever are in XX, but asymptomatic cases may not be). Agreed? My understanding of the AZ studies (despite all their other mistakes) is that participants were being tested weekly, regardless of symptoms. Is that incorrect, or are you suggesting something else? I definitely don’t want to repeating misinformation. Second Edit: after looking at table 2 in [1] and comparing the results to the common headline “about 60% effective” [2], it seems like media are reporting the “two standard doses” results. That might be what some folks end up doing, and it’s regretful that the study design went all over the place. Either way, thanks for the nuance! I will update my future comments to note that the confidence intervals including the asymptomatic results are wildly large, such that they need serious discounting. [1] https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32661-1/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... [2] https://www.bbc.com/news/world-europe-55862233 https://www.bbc.com/news/world-europe-55862233

by boulos 6y ago

xiphias2 6y ago

Also the results of this vaccine isn't that difference from just using 1 shot of another vaccine. It looks like as long as it's safe to do it, the 2nd shot is worth it.

m-ee 6y ago

They do not have different measures of eficacy. AZ did more testing to look at symptomatic infections but that was not used in the primary efficacy calculation. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32661-1/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

boulos 6y ago
I believe AZ was doing weekly testing while Moderna (maybe?) was doing “test if symptomatic”. That’s a huge difference.
- m-ee 6y ago
  If they didn't have symptoms, they weren't counted in the headline efficacy numbers we're talking about. "The primary outcome was virologically confirmed, symptomatic COVID-19, defined as a NAAT-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia)."
mlyle 6y ago
Just a nit: they don't have exactly the same outcome measure, definition of "severe", "symptomatic", etc. Nor were they conducted in the same, time, or the exactly same demographics. Nor did they use the same protocol: testing weekly with a swab and detecting and informing the participant of a positive status will get that person to report symptoms to the trial more often than if you don't. They use similar measures of efficacy but they're not the same thing and are not perfectly comparable. Still, it seems very likely that the mRNA vaccines are much better than AZ.
- m-ee 6y ago
  You’re absolutely right, but I didn’t want the overall message to get lost in the details. I’ve been seeing people parrot the “AZ is actually much better than it looks because they included asymptomatic patients” for months now and it’s just incorrect.
  - boulos 6y ago
    I’m honestly confused! Can you point me to your source for the excerpts in your sibling comments? Edit: reading your lancet link now (sorry about that). My understanding from reading the description of the Moderna results was “XX / YYY people developed covid; but we didn’t test everyone in the YYY set” (so people who definitely got it / went to a hospital / whatever are in XX, but asymptomatic cases may not be). Agreed? My understanding of the AZ studies (despite all their other mistakes) is that participants were being tested weekly, regardless of symptoms. Is that incorrect, or are you suggesting something else? I definitely don’t want to repeating misinformation. Second Edit: after looking at table 2 in [1] and comparing the results to the common headline “about 60% effective” [2], it seems like media are reporting the “two standard doses” results. That might be what some folks end up doing, and it’s regretful that the study design went all over the place. Either way, thanks for the nuance! I will update my future comments to note that the confidence intervals including the asymptomatic results are wildly large, such that they need serious discounting. [1] https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32661-1/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... [2] https://www.bbc.com/news/world-europe-55862233 https://www.bbc.com/news/world-europe-55862233