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Comment by version_five | Hacker News Reader

Stupid question, could this come down to the volume of the shot? I understand Moderna is ~3x as much as pfizer volume wise, otherwise I thought the method of action is roughly the same.

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Among other differences, Moderna dosages had ~3x more mRNA compared to Pfizer (100 v 30 micrograms), and their regime had longer periods between dosages. Apparently rationale for Pfizer doses was to minimize side effects because from their initial testing they did not find a significant increase in antibodies with a higher dosage [1].

[1] https://www.nejm.org/doi/full/10.1056/NEJMoa2027906

Not stupid at all. Yes this is the main theory as to why moderna wanes less than pfizer.

https://www.businessinsider.com/pfizer-lower-dose-moderna-co...

Other theory is Moderna has 4 weeks between doses vs 3 for Pfizer.

This is interesting. In canada we had a longer waiting time between the shots because of lack of supply. People who got it earliest (older, etc) generally had a 12 week waiting time I think though it may have been shortened as we got more supply. I got my first (pfizer) as soon as I was eligible, and could get my second 8 weeks later. I think people that got their first shot later could wait a much shorter time, i.e. the recommended 3/4 weeks. It would be interesting to see if its possible to disentangle the effects of the way they were rolled out in different countries to see how much of a difference timing makes.

And that Pfizer was supposedly given to older people (weaker immune system) versus the others.

Would be good to have adjusted studies.

This is interesting. Do you have a source for this?

Not a source but around here Pfizer was available first so the most at risk people got it.

This shouldn’t be downvoted, they are finding that waiting between the two doses longer does help.

There are broader points to be made about the voting system on HN, and the efficiency with which we're sorting information. It bothers me how little conscious time we spend improving the mechanisms of the places we discuss in.

If the sorting system were a little better at avoiding good comments being downvoted, when they are pointing out something not immediately obvious and agreeable, that would elevate the efficiency of discourse.

That seems more valuable than the time that has been spent on it would seem to indicate.

I think that's what they're all trying to do. The problem isn't the sorting system, it's the fact that a "good comment" can't be an objective thing in every possible context.

I feel like the error we have is in ranking down things that are uncertain. If it's a certainty, people will vote for it quite a lot more than if it isn't.

That is a mistake. I want to look at factual posts that are new to me, but also non-obvious posts. We burry non obvious posts more easily than we should, today, I think.

The current system on HN is not too bad, but it could do a slightly more subtler job of promoting ideas that take a little bit more effort before they seem obviously true, in retrospect.

We're too quick to hide the subtle and the uncertain.

Downvoting on HN is poorly implemented. It creates an unstable initial condition for a new comment. Downvote from initial 1->0 cascades into a snowball effect for ganering downvotes from other users who are pursuaded by the gray text. Similarly, if is upvoted from 1->2, then you have a strongly positive comment that will most likely stay positive.

Delaying the visual indicator of gray text for 1 hour would solve this problem. As it stands, it rewards pathological downvoters who continue to degrade healthy discussion on this site.

In a perfect world, we should be able to use a customized version of HN in which posts emerge according to our own algorithm.

I would pay to see what happens if the rating system used dynamic weighs favouring reputation.

Sources:

https://www.bmj.com/content/374/bmj.n1875

"It found that, after the second vaccine dose, neutralising antibody concentrations were higher after an interval of 6-14 weeks than after the 3-4 week regimen that was initially recommended.

When looking at the delta variant, researchers also noted that, though there were good levels of antibodies after the shorter dosing interval, levels were 2.3-fold higher with the longer dosing interval."

http://www.bccdc.ca/Health-Info-Site/Documents/COVID-19_vacc...

This isn't really "new" knowledge, double vaccine shots for other illnesses are usually spaced months apart because it usually boosts immune response and vaccine longevity. I feel quite fortunate that I got Moderna, spaced 7 weeks apart, here in Norway.

My comment comes from chatter I've seen from actual infectious disease specialist and my friend who's has a masters in public health. My friend was assuring people that getting the second dose 'late' wasn't going to be a problem.

Other chatter I've seen is that which part of the immune system does the heavy lifting varies depending on the infectious agent. With Covid it's the CD4 T lymphocytes that appear to what's important. Antibodies by themselves aren't that effective. (Notable antibody based therapy has been a bust with Covid19)

Depends where you get it. Here, it was 40 days between Moderna shots.

My Pfizer had 5 weeks between the shots. I wonder how that affects protection.

Indeed. To some extent, we can use pretty basic principles like the Law of Mass Action (https://en.wikipedia.org/wiki/Law_of_mass_action "In chemistry, the law of mass action is the proposition that the rate of the chemical reaction is directly proportional to the product of the activities or concentrations of the reactants.") to inform our priors on this. We should expect the Moderna one to be both somewhat more effective and have somewhat worse side effects simply due to the higher dose and similar action.

The other question is whether Moderna will also last approximately 3x as long as Pfizer, or if it's a far more nonlinear curve.

I’m sure it’s nonlinear to some extent as the immune system is complex. But you’d be surprised if there was zero effect of more dose.

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