Are there any examples of successful non-vaccine led herd immunity?

[Enrico]

Just that really. Are there any diseases whose circulation has dramatically reduced just by lots of people catching them, as opposed to by lots of people being vaccinated against them?

SciFi
That is really rather cool.
Have you contacted your local research hospital because the differences in your blood / system could give insights that save the lives of others.

It's pretty well known that some people (quite rare I think) can get chicken pox multiple times. The majority are immune for life after one infection. There are always exceptions to the rule - that's genetics!

Chicken pox is definitely more infectious among children than covid, and also more deadly. Covid is probably comparable with a cold to a certain extent, as a cold can certainly lead to pneumonia in vulnerable people, and as an asthmatic I have been hospitalised or on steroids following colds previously. The mystery is the small number of healthy people that die of the disease I guess.

“Diseases that kill too many people go extinct themselves”

This isn’t true. If they are infectious earlier on in the cycle then the disease gets transmitted and then the host dies.

Isn’t always true, I should say.

Manaus, Brazil. 60+% have had covid and apparently they have now reached herd immunity. About 1 in 500 have died however.

Can you only get chicken pox once?
I had it as a kid then again at 24 - much worse the second time.

Would the Black Death plague be an example? It went away somehow, was it immunity? I have no idea, I’m just pondering!
Obviously no one would think the way that went is an ideal plan for dealing with a pandemic though.

Manaus, Brazil. 60+% have had covid and apparently they have now reached herd immunity. About 1 in 500 have died however.
Link to validated stats for that please

@Frazzled13

Would the Black Death plague be an example? It went away somehow, was it immunity? I have no idea, I’m just pondering! Obviously no one would think the way that went is an ideal plan for dealing with a pandemic though.

I think the Black Death was through quarantining. This was possible IIRC because the symptoms appear pretty much as soon as the person is infectious. With many diseases the person is infectious for a period before symptoms and spreads it then.

I imagine it happens all time, otherwise life would have died out millions of years ago. We're not familiar with any of those diseases because they fizzled out once enough people had caught them. The pathogens we're aware of are the ones that are particularly good at evading our collective immune systems.

@ListeningQuietly

Manaus, Brazil. 60+% have had covid and apparently they have now reached herd immunity. About 1 in 500 have died however. Link to validated stats for that please

There’s news articles. Surprising.

www.google.co.uk/amp/s/www.sciencenews.org/article/coronavirus-covid-19-brazil-city-manaus-herd-immunity/amp

Manaus, Brazil. 60+% have had covid and apparently they have now reached herd immunity. About 1 in 500 have died however.
Link to validated stats for that please

www.medrxiv.org/content/10.1101/2020.09.16.20194787v1

@Tfoot75

It's pretty well known that some people (quite rare I think) can get chicken pox multiple times. The majority are immune for life after one infection. There are always exceptions to the rule - that's genetics!

Chicken pox is definitely more infectious among children than covid, and also more deadly. Covid is probably comparable with a cold to a certain extent, as a cold can certainly lead to pneumonia in vulnerable people, and as an asthmatic I have been hospitalised or on steroids following colds previously. The mystery is the small number of healthy people that die of the disease I guess.

Covid is not comparable to a cold. Please do not post 5his unless you can back it up with scientific evidence

interesting re Manaus
not peer reviewed and shocking fatality
nut interesting

Covid is not comparable to a cold.

"The estimated IFR is close to zero for children and younger adults but rises exponentially with age, reaching 0.4% at age 55, 1.3% at age 65, 4.5% at age 75, and 15% at age 85."

www.medrxiv.org/content/10.1101/2020.07.23.20160895v4#:~:text=The%20estimated%20IFR%20is%20close,and%2015%25%20at%20age%2085.

That's a very bad cold.

There are still outbreaks of the Black Death now and again, herd immunity doesn’t apply but it can be treated easily with modern medicine (antibiotics). See recent case below.

www.google.co.uk/amp/s/www.bbc.co.uk/news/amp/world-asia-china-53303457

Why "herd immunity" without a vaccine costs far more lives / cases

https://threadreaderapp.com/thread/1305436391707467776.html

Adam Kucharski @AdamJKucharski
(Mathematician/epidemiologist at LSHTM, WellcomeTrust)

A thread on the problem of 'overshoot'
......
two related, but different metrics:

the % of people infected during an epidemic,
and the point at which immunity leads to a decline in transmission

In an uncontrolled epidemic, 'herd immunity' is reached at the peak (because R

Herd immunity must have been reached in the past before vaccinations, otherwise diseases that wiped out most of the indigionous populations of colonised places would have wiped out the invaders too.

Didn’t work with smallpox, did it?

@notevenat20

Covid is not comparable to a cold.

"The estimated IFR is close to zero for children and younger adults but rises exponentially with age, reaching 0.4% at age 55, 1.3% at age 65, 4.5% at age 75, and 15% at age 85."

www.medrxiv.org/content/10.1101/2020.07.23.20160895v4#:~:text=The%20estimated%20IFR%20is%20close,and%2015%25%20at%20age%2085.

That's a very bad cold.

Covid is a virus that attacks the inflammatory and respiratory systems. It is not a bad cold. As people I know with long Covid, or died and dr and nurse friends who treated it would tell you.

The Black Plague still exists and can he treated with anti biotics. We mostly eradicated it with quarantine and then medicine.

It’s a bacteria not a virus so you can’t compare it.

We have struggled to contain any virus.

Many viruses live in us to re-emerge With reinfection... chicken pox, herpes, hiv.

There have been reports of reinfections of Covid and some have it worse second time. More studies need to be done before we know for sure though.

Suppressing the virus gives us time to look into this, the effects of long Covid, treatments, Vaccines...

Herd immunity usually needs a vaccine

@user1471588124

Herd immunity must have been reached in the past before vaccinations, otherwise diseases that wiped out most of the indigionous populations of colonised places would have wiped out the invaders too.

Smallpox, malaria, plague... all still exist.

Actually not smallpox. But vaccines defeated it.

Covid is a virus that attacks the inflammatory and respiratory systems. It is not a bad cold. As people I know with long Covid, or died and dr and nurse friends who treated it would tell you.

Yes. In case it wasn’t clear I was mocking the idea that it was like a cold. The deaths figures I quoted make that clear.