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The UK’s delta surge is collapsing

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Re: The UK’s delta surge is collapsing

#311
post #232

Earlier quoted context omitted.

Is there a reason we shouldn't expect it to behave like most coroanviruses?

There actually is. The evolutionary selection pressure on most coronaviruses exists throughout its infectious stage. So in order to be more infectious for longer the coronavirus would become less symptomatic and so less serious. But with C19 we are aggressively isolating people with symptoms. This focuses evolutionary selection pressure on the initial infectious stage. In order to be more infectious the virus increas…

Are you saying without lockdowns it would have turned in a regular cold by now?

Re: The UK’s delta surge is collapsing

#312
post #90

Most news articles I see focus solely on the number of vaccinated people when estimating how far away countries are from herd immunity, which seems odd to me. Left out in the discussion seem to be the unvaccinated but already infected. As far as I know, prior infection confers at least some degree of immunity. It may also be the case that those inclined to be skeptical of vaccines were also the ones who exposed thems…

The herd immunity threshold changed with Delta, which I've heard has an R0 of 8-10 (compare 3.5-4.5 for the UK Alpha variant, and about 2.5 for the original strain). Instead of 60% vaccination, you'd need 90%, and will likely overshoot that. It wouldn't surprise me if the UK's cases are now dropping because they reached that threshold, but I doubt the US is there now. Probably Delta will blow through literally all th…

>at least unless we get a vaccine-resistant strain.

...which will happen promptly. The selection pressures are perfect. You already have a variant with vaccine breakthrough, circulating in a partially vaccinated population.

Re: The UK’s delta surge is collapsing

#313

Earlier quoted context omitted.

The current vaccines will not prevent kids from spreading the virus to their grandparents.

It's not about preventing. It's about reducing probabilities. The vaccines do not prevent kids from getting it. They do not prevent adults from getting it. They do not prevent people from spreading it. They do not prevent people from getting hospitalized or dying from it. They decrease the chances of all of the above happening.

The real-life efficacy at preventing transmission is waning by the day, it seems.

Re: The UK’s delta surge is collapsing

#314

Earlier quoted context omitted.

Other than people with compromised immune systems, or people who are trying not to spread the virus to small children for whom the vaccine isn't approved yet. I'm all for being annoyed people who could get the vaccine but decided not to, but we shouldn't throw the actual babies out with the proverbial bathwater, right?

We're not talking about literally killing them. We're talking about leaving them to their own devices. They can get vaccinated at any time. Why should the rest of us be locked down, now that we have effectively ended the overrun of hospitals? Wasn't that what this was all about? Who cares if people get the coronavirus? All that matters is not developing severe SARS-Cov-2.

What about my posts has given you the impression that I care about the people who could get vaccinated but haven't? I've repeatedly expressed my annoyance there. However, we should do our part to minimize spread at least until kids can get the vaccine. In particular, it seems to be the case that the Delta variant can spread from a vaccinated person to an unvaccinated one, so if there's widespread infection people could get it, then give it to their kids.

Anyway, all I'm doing is sticking to restaurants that have outdoor seating, wearing my mask in stores, and keeping distant from strangers on the sidewalk, so it is pretty relaxed compared to the height of the non-vaccinated pandemic.

Re: The UK’s delta surge is collapsing

#315

Earlier quoted context omitted.

The reason to not want children to get COVID is that they will spread it to their parents and grandparents, who are more vulnerable. It’s not about whether the children will die, which everyone agrees is very low probability.

It’s an interesting point, and I’m relatively neutral on all the underlying empirical claims. But taking the assumptions as a given, doesn’t this violate the Hippocratic Oath? Physicians are ethically forbidden from recommending a medical treatment that’s a harm to the patient, even if it’s in the interest of society.

>Physicians are ethically forbidden from recommending a medical treatment that’s a harm to the patient, even if it’s in the interest of society.

Vaccines work at the population level, physicians don't check if you're going to benefit, society benefits. That is still ethical, depending on the ethical framework. I don't think doctors truly hold the Hippocratic Oath as ground truth, most probably don't believe in Apollo, for example.

Re: The UK’s delta surge is collapsing

#316
post #303

Earlier quoted context omitted.

U.S. is only at 50% fully-vaccinated, with several states in the high 30s to 40s. I could believe 70% with at least one shot but haven't seen any statistics to that effect; it doesn't matter much since Delta is still pretty dangerous to partially-vaccinated people. We had 35M recorded COVID cases; I'd believe about a 2:1 undercount, so about 70M total cases (~22%). Vaccines + previous cases was likely past herd immun…

> I could believe 70% with at least one shot but haven't seen any statistics to that effect Good guess. As of today, that's the exact number: https://www.usnews.com/news/health-news/articles/2021-08-02/...

Just for clarity, that's "70% of American adults".

18% of Americans are 15 or younger [1], below the youngest approved vaccine age (the Pfizer vaccine is approved for teenagers as young as 16), so that's (0.18 + (1-0.18) * (1-0.7) = ) ~42% of Americans who haven't even received 1 shot, and 58% who have.

(There may be some error in that, if far more or far less than 70% of non-adult vaccine-eligible people (teenagers aged 16 or 17) have gotten at least one shot, but it probably doesn't change the overall percentage that much.)

[1] https://www.cia.gov/the-world-factbook/field/age-structure

Re: The UK’s delta surge is collapsing

#317
post #312

Earlier quoted context omitted.

The herd immunity threshold changed with Delta, which I've heard has an R0 of 8-10 (compare 3.5-4.5 for the UK Alpha variant, and about 2.5 for the original strain). Instead of 60% vaccination, you'd need 90%, and will likely overshoot that. It wouldn't surprise me if the UK's cases are now dropping because they reached that threshold, but I doubt the US is there now. Probably Delta will blow through literally all th…

>at least unless we get a vaccine-resistant strain. ...which will happen promptly. The selection pressures are perfect. You already have a variant with vaccine breakthrough, circulating in a partially vaccinated population.

I don’t know if you can make that bet - evolution of the virus needs to conserve the current mode of cellular entry and attachment and fitness of spike appears to be the main driver at present - and then spike mutation has driven drift from the original vaccine target leading to a degree of immunity ‘escape’.

So the question is, is the virus now in a local minima where it is highly adapted for spread (ie big increase in R0 from ‘original’ virus) and are those selective pressures in a situation where the virus can’t jump into a full immunity escape mode without climbing down off mount improbable and taking another face?

My bet would be that the selective pressures may continue to drive fitness for reproduction, but won’t lead to immunity escape because spike is too conserved

Re: The UK’s delta surge is collapsing

#318
post #312

Earlier quoted context omitted.

The herd immunity threshold changed with Delta, which I've heard has an R0 of 8-10 (compare 3.5-4.5 for the UK Alpha variant, and about 2.5 for the original strain). Instead of 60% vaccination, you'd need 90%, and will likely overshoot that. It wouldn't surprise me if the UK's cases are now dropping because they reached that threshold, but I doubt the US is there now. Probably Delta will blow through literally all th…

>at least unless we get a vaccine-resistant strain. ...which will happen promptly. The selection pressures are perfect. You already have a variant with vaccine breakthrough, circulating in a partially vaccinated population.

Measles, polio, and smallpox beg to differ. The varicella vaccine is fairly new, but I haven’t heard of a vaccine-resistant strain evolving. Pertussis seems to be an odd duck, and its vaccine is not as effective as people would like.

History is mixed here, but most of the mandatory vaccines seem to be extremely effective and to work well for at least decades.

Re: The UK’s delta surge is collapsing

#319
post #312

Earlier quoted context omitted.

The herd immunity threshold changed with Delta, which I've heard has an R0 of 8-10 (compare 3.5-4.5 for the UK Alpha variant, and about 2.5 for the original strain). Instead of 60% vaccination, you'd need 90%, and will likely overshoot that. It wouldn't surprise me if the UK's cases are now dropping because they reached that threshold, but I doubt the US is there now. Probably Delta will blow through literally all th…

>at least unless we get a vaccine-resistant strain. ...which will happen promptly. The selection pressures are perfect. You already have a variant with vaccine breakthrough, circulating in a partially vaccinated population.

I'm not sure if it's inevitable given how crucial the spike protein is and how strongly it is being conserved. Even with the Delta variant, which is much more infectious and contagious, the vaccines are only modestly less effective and still highly effective at preventing severe illness and death.
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