The mutation that helps Delta spread • Hacker News Board

Re: The mutation that helps Delta spread

#81

Post by chinathrow » Fri, Aug 20, 2021, 7:31 PM UTC

Retric wrote: post #53

nradov wrote: post #37

Earlier quoted context omitted.

Right which is why achieving any meaningful level of herd immunity is now effectively impossible. Thus we're all likely to get infected eventually. https://www.businessinsider.com/delta-variant-made-herd-immu... Fortunately the vaccines are very effective at preventing death for all variants.

Herd immunity happens long before we are all infected. Less than 40% of the US population is completely unvaccinated, which means we can open up more without overwhelming hospitals. That does put the unvaccinated at increased risks, but the general public is seemingly unwilling to continue lockdowns to protect people choosing not to be vaccinated. If ~85% is needed for herd immunity then we could be rapidly approachi…

> Less than 40% of the US population is completely unvaccinated, which means we can open up more without overwhelming hospitals.

Not sure where you get this about open up, but have you seen current ICU fill levels in various US states such as Alabamba etc?

Re: The mutation that helps Delta spread

#82

Post by nradov » Fri, Aug 20, 2021, 7:32 PM UTC

Retric wrote: post #53

nradov wrote: post #37

Earlier quoted context omitted.

Right which is why achieving any meaningful level of herd immunity is now effectively impossible. Thus we're all likely to get infected eventually. https://www.businessinsider.com/delta-variant-made-herd-immu... Fortunately the vaccines are very effective at preventing death for all variants.

Herd immunity happens long before we are all infected. Less than 40% of the US population is completely unvaccinated, which means we can open up more without overwhelming hospitals. That does put the unvaccinated at increased risks, but the general public is seemingly unwilling to continue lockdowns to protect people choosing not to be vaccinated. If ~85% is needed for herd immunity then we could be rapidly approachi…

With an R0 of about 6 for the Delta variant, herd immunity won't provide a meaningful level of protection for most people. Herd immunity works with less contagious diseases because susceptible individuals can go their whole lives without exposure. But with SARS-CoV-2 now being endemic worldwide we'll all eventually get exposed, it's just a question of when. So the smart move is for everyone to protect themselves by getting vaccinated and actively treating co-morbid conditions like obesity, diabetes, hypertension, and hypovitaminosis D.

Any further lockdowns at this point cause far more harm than benefit.

Re: The mutation that helps Delta spread

#83

Post by rudedogg » Fri, Aug 20, 2021, 7:32 PM UTC

naasking wrote: post #36

nonbirithm wrote: post #6

Is it implausible to think that continued transmission and mutation at this rate will cause a catastrophic worsening of the pandemic to an extent several orders of magnitude above what it is now? Vaccination is effective in the current state of the pandemic, but what's to prevent the built-up immune response of humankind being wiped out if the virus adapts enough?

Not implausible at all. Mutation rate is proportional to the number of infected. Third world countries have barely even started vaccinating. There's a lot of room for nightmare scenarios. Which is why I think it was a bone-headed move to not suspend patent protection on the vaccines. Thanks Bill Gates!

The Bill Gates mention set off my conspiracy nut alarm bells, but after reading this entire article[0] the criticism seems fair.

[0] https://www.devex.com/news/gates-foundation-reverses-course-...

Re: The mutation that helps Delta spread

#84

Post by tunesmith » Fri, Aug 20, 2021, 7:32 PM UTC

Retric wrote: post #53

nradov wrote: post #37

Earlier quoted context omitted.

Right which is why achieving any meaningful level of herd immunity is now effectively impossible. Thus we're all likely to get infected eventually. https://www.businessinsider.com/delta-variant-made-herd-immu... Fortunately the vaccines are very effective at preventing death for all variants.

Herd immunity happens long before we are all infected. Less than 40% of the US population is completely unvaccinated, which means we can open up more without overwhelming hospitals. That does put the unvaccinated at increased risks, but the general public is seemingly unwilling to continue lockdowns to protect people choosing not to be vaccinated. If ~85% is needed for herd immunity then we could be rapidly approachi…

There's math you can do to roughly judge impact of partial vaccination. If R0 is six, and you're looking at hospitalization, estimate vaccine efficacy for Delta at around 90% (I've seen estimates above and below that).

Taking your estimate of a 60% vaccination rate:

6 * (1 - (.6 * .9)) = 2.76

2.76 is the effective Rt, which is far above 1, so no, that is not enough to open up more without eventually overwhelming hospitals.

Natural immunity from catching COVID, and other (inherently temporary) mitigation measures like masks/distancing/lockdowns would bring that Rt down further. But clearly what is best is more vaccination.

Re: The mutation that helps Delta spread

#85

Post by empthought » Fri, Aug 20, 2021, 7:32 PM UTC

achenatx wrote: post #54

cjfd wrote: post #24

Earlier quoted context omitted.

Both the worst-case and the best-case scenario are on the table. Only time will tell what happens. As you seem to be focusing on the worst-case scenario I will talk about the best-case scenario. The best-case scenario is that the human immune system is getting used to corona with even vaccinated people spreading the delta variant with little chance of getting very ill. This will turn covid-19 into something like the…

The likely scenario is that it turns into cold/flu. Everyone either gets the vaccine or the virus and we are all mostly immune. It mutates a little and once it mutates just enough to spread substantially everyone who gets it gets immune. Only a fraction of the population will get any particular mutation. I remember having the debate that herd immunity has never happened without a vaccine. Which is just BS. Every dise…

You don't understand what "herd immunity" means. Herd immunity means eliminating a disease within a community ("herd"). It does not mean endemic case incidence with socially tolerable outcomes, or whatever loosey-goosey idea you mean by "equilibrium."

Herd immunity means the contagion is eliminated. It has never happened worldwide without a vaccine, and I'm unaware of any virus where it has been sustained within a community without a vaccine. How could it? The only paths to immunity are vaccine or exposure, and exposure depends on the virus actually circulating.

Re: The mutation that helps Delta spread

#86

Post by seaman1921 » Fri, Aug 20, 2021, 7:32 PM UTC

cmrdporcupine wrote: post #77

hutzlibu wrote: post #61

I see the sentiment here expressed, that Covid is far from over. To be honest, I stopped following news since being fully vaccinated some time ago, so I am kind of ignorant here. Is the main problem, the unvaccinated, or that the Delta (and co.) variants are still, too dangerous for vaccinated people? Or is it the fear, that they will get more dangerous?

So here in Ontario where we're @ about 65% of the population totally vaccinated, today's new cases. Source: https://data.ontario.ca/dataset/covid-19-vaccine-data-in-ont... 10.25/100k among people who are unvaccinated. 6.5/100k among people who are partially vaccinated. 1.0/100k among people who are fully vaccinated. For hospitalization: 2.04/100k for unvaccinated, 1.11/100k for partially, 0.21/100k for vaccinated. Fo…

thank you for the numbers!

But i think you got them wrong > 10.25/100k among people who are unvaccinated that should be 10.25k - so your statement at the end about 10% ICU admissions does not hold.

Re: The mutation that helps Delta spread

#87

Post by marricks » Fri, Aug 20, 2021, 7:32 PM UTC

polynomial wrote: post #59

marricks wrote: post #29

Earlier quoted context omitted.

I'm not sure "only twice as bad" paints an accurate picture. - Herd immunity is much harder. Calculated as 1 - 1/r0 where r0 is defined in relation to transmissibility. So if r0 = 3 that's ~66% need to be immune to stop the virus. If r0 = 6 that's 83% needed, much higher threshold. - The virus is only getting more deadly. A preprint study found delta has "120% greater risk of hospitalization, 287% greater risk of ICU…

Do we have generally accepted R0 values for each of these 3 variants?

I think there's am R0 for initial strain and then ranges for the other variants. I thought it was in Wikipedia but either it's been edited out or I saw it elsewhere.

What I recall (so huge grain of salt here) was R0 at 2.3 for initial strain then around 2x for Alpha and another 2-3x for Delta. Not. Great.

Re: The mutation that helps Delta spread

#88

Post by Filligree » Fri, Aug 20, 2021, 7:33 PM UTC

hutzlibu wrote: post #61

I see the sentiment here expressed, that Covid is far from over. To be honest, I stopped following news since being fully vaccinated some time ago, so I am kind of ignorant here. Is the main problem, the unvaccinated, or that the Delta (and co.) variants are still, too dangerous for vaccinated people? Or is it the fear, that they will get more dangerous?

> Is the main problem, the unvaccinated, or that the Delta (and co.) variants are still, too dangerous for vaccinated people? Or is it the fear, that they will get more dangerous?

Lots of problems.

- The virus causes serious sequela; people who have been infected may have life-long damage, and some of that damage looks really bad. There's little correlation between severity of the initial infection and severity of the damage, so we don't know if vaccines help either.

- Not all people can be vaccinated. Young children can't be (their immune systems don't work the same way), people with some other underlying diseases can't be, etc. It's by no means just anti-vaxxers who are at risk.

- People aren't dying enough. Historically, this sort of pandemic only ended once the people who were genetically at risk had all died, and we're not letting that happen. Now, to be very clear: I'm not saying we should!

- Having a vaccinated population intermingling with an infections population means there's immense pressure on the virus to evade those vaccines. Many of the means by which it might do so will make it far more deadly to anyone who isn't vaccinated; Delta, for example, has adopted 'human wave tactics' to overwhelm the antibodies.

However, this does mean that history is a poor guide to what might happen.

Viruses don't generally have any reason to want their hosts dead, but there's also little evolutionary pressure for having that not happen.

We're helpfully adding pressure that's well suited to make it more deadly. Yay.

Re: The mutation that helps Delta spread

#89

Post by schmichael » Fri, Aug 20, 2021, 7:33 PM UTC

hncurious wrote: post #70

Covid is going to be endemic like the flu and cold. It's not going to be eradicated, unfortunately, and I don't think we've come to terms with this yet. Now what's our plan exactly? Get vaccinated every 6 - 12 months indefinitely and always wear masks? What's our goal and what's our new normal?

I already get vaccinated every 12 months for the flu, so that seems like a fine plan to me.

Re: The mutation that helps Delta spread

#90

Post by delecti » Fri, Aug 20, 2021, 7:33 PM UTC

hncurious wrote: post #70

Covid is going to be endemic like the flu and cold. It's not going to be eradicated, unfortunately, and I don't think we've come to terms with this yet. Now what's our plan exactly? Get vaccinated every 6 - 12 months indefinitely and always wear masks? What's our goal and what's our new normal?

> Get vaccinated every 6 - 12 months indefinitely and always wear masks

An annual Flu and COVID shot seems perfectly reasonable. Wearing masks in public is already normal (or at least not uncommon) in many places, and I don't have a problem with where I live being one of those places.