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Comment by anyfoo | Hacker News Reader

A less effective vaccination keeps COVID around longer and farther than a more effective one, though, giving the virus more time and population surface to mutate into further variants. (But still less than no vaccination.)

I'm not an expert in this, so I cannot say how significant that issue is, but this is at least one potential downside that I am seeing to the vaccination being weaker for that variant.

EDIT: To clarify since some have misunderstood: I did not assert that the vaccination causes higher mutation, quite the opposite. I asserted that the absence of vaccination (entirely or effectively) gives more opportunity for mutation. I understand now that there are higher order effects that make this more complex.

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Is it analogous to flu? Do flu vaccines cause mutations as well?

One interesting thing about covid is that it seems to be the first time humanity has collected so much data (eg. contact tracing, phylogenetics through genome sequencing, etc.) about this kind of virus, and applied modern medical knowledge in trying to combat it.

It's very apparent that the overall response hasn't been nearly good enough, but it's probably also the best response there's ever been. (perhaps not the best ROI, though?)

> Do flu vaccines cause mutations as well?

That is not what I have written, please reread!

That's a fair critique. I feel like I've heard concerns about the potential for the virus to mutate because of the high level of vaccinations, but like you, I don't know how significant of an issue that is.

I think the parent was talking about the lack of vaccinations yielding more time to mutate, not the vaccinations themselves. Viruses aren't like bacteria; they don't mutate in direct response to vaccines.

That is correct. My premise was that the more virus exists in absolute numbers (if the vaccine is weaker for the Delta variant), the more virus has the opportunity to mutate.

I also have this concern. I haven’t seen it addressed anywhere and I am but a mere layperson.

What you've heard is misinformation. Vaccines reduce potential for mutation, which is both intuitive and borne out by data.

That's neither intuitive nor true in all cases.

https://www.quantamagazine.org/how-vaccines-can-drive-pathog...

Just to clarify: That is not my concern.

the fact that the delta variant came from a country that didn't have widespread vaccines dispels this notion.

Seems perfectly in line with what I said? More virus, more time to mutate -> more mutations?

I now understand that there are second order effects that make this more complex, but I don't see the contradiction right here.

I suppose either you edited it to change the text or the more likely event was that I misread it. yeah you're mostly correct and there are those second order effects too.

It's going to mutate regardless of how many people are vaccinated. The entire point is to make it so that people don't have the runaway immune system responses that are melting lungs and brains.

Is that true? Intuitively, the more virus exists (in absolute numbers, even), the more virus may potentially mutate into worse variants. More infected people -> more individual virus instances, each with a given chance to mutate, and more time for that mutation to occur (because expired virus is replenished with fresh virus in available hosts; though you can probably fold this into higher virus numbers instead with the same result).

I'm gladly corrected if I missed something!

Variant that achieve immune escape from vaccine-induced immunity are bound to propagate at a faster rate if most people are vaccinated.

Even if that variant is more lethal (from which you might expect a smaller R0), it might be prevalent because of an augmentation in R0 from vaccination (which might be lesser had people developed a more complete natural immunity).

The likelihood of mutation is directly proportional to how widespread a virus is multiplied by the amount of time it stays that way (more specifically, the area under the curve for infections over time). Vaccination and control of spread is critical to preventing further variants

Likehood of mutation might be, but spread of variants is a more complicated function. Vaccination for sure might affect how likely one variant predominates against others.

Considering cross-immunization between variants with natural immunity, it might be more efficient to refrain from vaccines to give cross-immunity with a weaker variant.

This isn't really true. For instance, it's been shown that mutations are far more common in immunocompromised people (many of whom cannot even take the vaccines) where the virus can just camp out for months and train itself against the human immune system. So one particular host might serve as a more fertile environment for variants than thousands of others combined.

https://www.washingtonpost.com/health/2021/03/11/immunocompr...

Doesn't this mostly depend on 3 things?

1. Likelihood of breakthrough infections.

2. Mutation rate.

3. Initial volume of infections.

For instance, if the likelihood of breakthrough infections is low enough to overcome the reproduction rate, the mutation rate is slow enough, and the initial volume of infections low enough, you'd expect that the virus would die out if enough people have had the vaccine, right?

On the other hand, if the likelihood of breakthrough infections were high, mutation rate were high, initial volume of infections high, makes sense that you would expect to see ongoing mutation.

Another way I think this might go is that mutations happen & breakthrough infections happen, but the breakthrough infections further boost immunity, and the severity never re-approaches the original severity of covid.

Only if you ignore the fact that viruses compete for hosts.

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