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Comment by starik36 | Hacker News Reader

I am not sure that it's a good explanation. Just the opposite.

J&J's excuse for 66% effectiveness is that they were tested when there was more Covid going around? That's exactly when the vaccine is supposed to protect you. Not when there isn't an opportunity to catch the disease.

And if we then take this claim on its face, then Pfizer and Moderna vaccine stated effectiveness is pointless, since it wasn't tested during the worst times.

Finally, the claim that no one in the study group that did catch the virus ended up in the hospital is also based on self-selective bias. I am assuming people in the study were younger people who needed the money and not older folks who are at a higher risk. I am not saying that it's not true - just that the biases need to be taken into account in any study.

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> I am assuming people in the study were younger people who needed the money and not older folks who are at a higher risk.

That may be true in the earlier phases, when you are just trying to show that the vaccine isn't too harmful and works in at least some cases.

It's not true for the large phase 3 trials. For those you try for a study group that matches the demographics of the people who will be getting the vaccine in the wild.

For the J&J phase 3 trial, 34% of the participants were over 60. 41% had comorbidities associated with an increased risk for progression to severe COVID. Race was 74% white, 13% black, 6% Asian, and 1% Native American. Ethnicity was 15% Hispanic.

Pfizer was 45% age 56-85, Moderna was 16% over 65. Race for both was about 80% white, 10% black, 4-5% Asian, 1% Native. Ethnicity was 26% Hispanic for Pfizer, 20% for Moderna. I don't know what percent had comorbidities.

There are 2 reasons for JNJ’s lower top line numbers.

1) There were more of the variants going around, not more of the original strain going around when JNJ was tested and all the vaccines are less effective against the variants. PFE and MRNA were tested when only the original strain was going around. All the vaccines were designed to combat the original strain.

2) JNJ doesn’t protect as well against mild Covid. But the symptoms from this mild Covid are comparable to the side effects from the second dose of PFE/MRNA which affect 30-40% of people and based on anecdata from people I know nearly everyone.

1 is false - this article's 91% includes data from before, during, and after the J&J trial. So it covers times when the variants were more active as well.

My original comment referred to the 95% effectiveness in PFE top line numbers from when we got the clinical trial readout rather than the 91% in the article. I was responding to the parent comment.

Further, the JNJ clinical trial data was from a population where the Brazilian variant, the most serious of the variants, was likely more widespread than this PFE data which seems to focus more on the relatively less dangerous South African variant.

A mild reaction to the vaccine is way different than actually having a viral infection. Potential long term persistent symptoms can occur with viral diseases and particularly COVID. Not sure that comparison makes sense.

Additionally JNJ has side effects as well.

> I am assuming people in the study were younger people who needed the money and not older folks who are at a higher risk.

I'm a participant in one of the J&J Ensemble trials. There is no payment associated with my participation.

Thanks. Good to know. Might I find out why you signed up?

I would have signed up myself for free - a 50% chance to get a promising vaccine now instead of waiting? They weren't doing studies in my area, so I had to wait until after the study for a vaccine to be offered to me.

I'm pretty young and fairly healthy, so a licensed vaccine was a long way off (and still is) for me personally. The 50% chance of possible protection from Covid-19 was something of a selfish motivator, but more generally it seemed like a good thing to do to try and help society return to some sort of normality (I work in a sector which has been hit quite badly) - of course, there was probably no shortage of volunteers so my space likely would've been filled without my participation.

It also seemed like a kinda fun thing to do, though - I find medical sciences pretty interesting and had read through and familiarised myself with the phase 1 & phase 2 trial results for Ad26.COV2.S. I thought it'd be an interesting experience and the risks seemed acceptable to me.

The only downsides so far have been the distance I have to travel to get to the clinical research facility and the fact that I don't really like the sight of blood. I've had so many blood tests (in this study and outside) that I'm fine with the process, but I prefer not to watch.

No payment? You're getting ripped off! In my area, it's $150 per appointment.

A recent "real-world" study done in the US between mid-December to mid-March found that people vaccinated with either Pfizer or Moderna's vaccine show 90% protection against SARS-CoV-2 . Here you can read more about it. https://www.statnews.com/2021/03/29/real-world-study-by-cdc-...

> That's exactly when the vaccine is supposed to protect you. Not when there isn't an opportunity to catch the disease.

Are they saying the other vaccines were tested when you had lower chance of multiple exposures, and they were tested when there was higher chance, and it isn't controlled for in coming up with that number?

Correct. That’s what the video states.

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