If the Spanish Flu only infected 25% of the US pop, why is herd immunity even being discussed

[Quixote1818]

as a solution? If we can't do better today than we did over a century ago with as little as we knew about disease then, won't we have failed? Unless the infection rate was super low that is but I can't find any stats on that.

https://www.livescience.com/spanish-flu.html

[unblock]

1. deadliest but only because world population was so large by then.

the black plague took out a minimum of 15% of the entire world population, making it about 10 times more lethal than the 1918 pandemic, on a percentage basis.

[Calculating]

4. Yeah, the black death would've killed billions today

.

[SWBTATTReg]

2. There has been a DU discussion that 'herd immunity' doesn't even exist. I forget the trend, but...

might want to search for, it had some interesting info. in it. I was somewhat surprised, being that I have read articles right and left on 'herd immunity' and then I ran across that particular DU article that there is no such thing as 'herd immunity'.

[Igel]

3. "The Earth is hollow. Aliens live inside."

There, you've read that on DU, too.

Two claims have been advanced.

1. Somebody declared that "herd immunity" was a myth because not everybody would be protected.

That is true, but only if you take it upon yourself to redefine "herd immunity" for everybody to make it so everybody has to be immune. The usual definition of "herd immunity" is that it's widespread enough immunity (from whatever means) that transmission doesn't occur. It there's a hot spot, it dies out quickly without anybody doing anything.

2. Herd immunity is what you get when natural selection ensures that future generations have an inherent immunity. We have measles herd immunity, the claim is, because measles has been around for us to have adapted to it so we no longer can catch it.

Some things are just absurd enough that there's no point trying to do anything but say,

Let's just say that if we didn't vaccine people against measles for 20 years, there'd be a hell of a measles epidemic.

[SWBTATTReg]

8. I didn't say that I believed in herd immunity, I simply said said someone had posted an article on

it. Thanks though, for the additional information on the well known value of vaccines, and your take on the so called 'herd immunity' thesis.

There are obviously several schools of thought out there on herd immunity (actually I'm sure there are many schools of thought on this, I'm not an expert).

In both England and Sweden, they are letting CV to go ahead and run loose/amuck/somewhat controlled,
and build enough of an immunity amongst the population to escape the most severe characteristics of the CV. I don't really agree w/ this approach, but they obviously have some very qualified people that believe otherwise, which is why they took the approach they did. We'll see, they have 100,000s of people infected in Stockholm already, I don't know about this.

I grew up w/ Polio and the impacts that polio had on people affected relatives and neighbors of mine. The vaccine was important, very important, and a national effort to vaccinate all was undertaken for polio. I guess many don't remember this.

My version of 'herd immunity' may be really 'species' immunity, in that some genetic abilities are developed by particular species to process certain substances (such as cellulose) and others do not develop this type of ability, over long periods of time. Another is that our skin, via the sunlight, create vitamin D for use by our bodies. I'm sure that there are lots of other similar processes going on in every species.

I've read multiple articles out on this very topic, so to just dismiss the 'herd immunity' concept offhand, I won't. I'll still listen, and add the 'information' whether valid or not to the other information that I've accumulated, to satisfy the trait of curiosity that we as humans, all have.

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6. herd immunity is essentially what a vaccine relies on

you can get immunity artificially by getting a vaccine, or you may be able to get it by being naturally exposed to the virus (still to be determined if this really gives effective immunity, or how long it may last).

either way, if enough of the population get the vaccine (herd immunity), then it's no longer a pandemic, because if someone gets sick, they can't spread it around very effectively because 80% of the people they expose the virus to now has immunity. so instead of every sick person passing it on to 3 other people, they only pass it on to around 0.6 people (the 20% of the 3 people who didn't have immunity), so yes, it spreads around to a few other people, but the spread peters out quickly.


the cynical right-winger hope is that ordinary people spread it around enough to get to that 80% level (again, this assumes that natural exposure to covid-19 actually gives meaningful immunity), thereby making it much safer to return to normal, and they just don't care that this approach may mean many, many unnecessary deaths.

[SWBTATTReg]

9. Well said. NT

[Igel]

5. Herd immunity's being discussed, as far as I can tell, for one primary reason.

It's assumed that this will be squashed through one of two ways.

1. A vaccine is produced. Or more than one vaccine.

2. No vaccine is produced and the virus doesn't just quietly die away or mutate itself into a virus with a nice personality. If this is the case, it will go around and come around until it can't any more.

"Until it can't any more" means that chains of tranmission automatically peter out with people who are immune. In other words, herd immunity.


Might it mutate and the mutation be a better breeder than the nasty version? Sure. Not going to bet that way.

Might it be possible to just shelter until the last person to be ill with it recovers and is no longer infectious? Sure. But that last person might be in the Congo, in Urdmurtia, someplace in the Amazon, or maybe in a little town in Idaho. And instead of dying out, that person may visit a number of cities on college visits and infect 50 people, 25 of them asymptomatic, with no way to trace. Then you get a bunch of hotspots and run the risk of it starting up again.

We might be able to squash it in the US. Yeah for us. But then as long as there are infectious people in the rest of the world we'd have to screen everybody that enters. And since you can be infected and not even test positive for a day or two, that means you get to quarantine everybody for at least a few days. And double check every negative test, just in case. Then triple check and quadruple check.

Because there'd be a large group of people here with no herd immunity that would be yummy for the virus to breed in. That's Taiwan. They're going to have to be really careful allowing people in--but they can, because it's an island. S. Korea, too. But the only border it has, really, is with N. Korea. New Zealand's doing a great job, 1000 miles by water from anybody. Poland's got fewer deaths than Germany and it's closed its border--but Germans and Poles, you know, they tend for the most part to not try to illegally immigrate or emigrate. It's not just a huge problem.

How do you prevent people from coming into the US that aren't screened and tested and quarantined? You'd have to be a super-Trump for that, any all the people that fought Trump on that point are no way going to reverse course and say Trump was a bad person because he wasn't stringent enough. But that means it's fairly easy for asymptomatic people not only to get into the US, but once in the US vanish because they fear deportation.

That leaves herd immunity and flattening the curve. Which was intended to keep the process of building up herd immunity at a low roar so as not to overwhelm the hospital system (which never actually happened in the US--people shifted the definition to emotional as opposed to logistical grounds) or until a vaccine is developed to provide the same effect artificially.

[crickets]

7. K&R for the post and the discussion.