Coronavirus

[jfman]

Originally Posted by 1andrew1

Final nail in the coffin for those believing in herd immunity.

https://www.ft.com/content/f75418a9-...2-758635e906b1

Oh I’m sure they’ll still be out there howling at the moon with those who claim 5G is a mind control device run by the CIA.

[nomadking]

Originally Posted by 1andrew1

Final nail in the coffin for those believing in herd immunity.

https://www.ft.com/content/f75418a9-...2-758635e906b1

1) The immune system works by eventually stopping production of antibodies, because they are no longer needed. The required antibody is "memorised" and produced, if and when it is needed. Think about it, it would be ridiculously wasteful of the immune system to constantly produce antibodies for something, it's never ever going to need again.
2) Seasonal flu reoccurs because the virus mutates and presents itself as a new virus. Think about it again, if each year it was the same virus, they wouldn't have to come up with a new flu vaccine each year. There would be just one that was used again and again.
3) Even if any vaccine only works for a few months, that should be long enough for the virus to die out. It would be unable to reproduce.
4) If herd immunity wasn't a fact, then people would've still been dying from Spanish Flu for the past 100 years.

[1andrew1]

Originally Posted by nomadking

1) The immune system works by eventually stopping production of antibodies, because they are no longer needed. The required antibody is "memorised" and produced, if and when it is needed. Think about it, it would be ridiculously wasteful of the immune system to constantly produce antibodies for something, it's never ever going to need again.
2) Seasonal flu reoccurs because the virus mutates and presents itself as a new virus. Think about it again, if each year it was the same virus, they wouldn't have to come up with a new flu vaccine each year. There would be just one that was used again and again.
3) Even if any vaccine only works for a few months, that should be long enough for the virus to die out. It would be unable to reproduce.
4) If herd immunity wasn't a fact, then people would've still been dying from Spanish Flu for the past 100 years.

Agreed. In this context we're talking about the study showing that natural herd immunity for CV19 does not exist. i.e., the belief that herd immunity can be acquired without a vaccine by letting Covid 19 run through the majority of the population unhindered in place of the current social-distancing, lockdowns, masks etc is called out as false by this study.

Originally Posted by 1andrew1

Agreed. In this context we're talking about the study showing that natural herd immunity for CV19 does not exist. i.e., the belief that herd immunity can be acquired without a vaccine by letting Covid 19 run through the majority of the population unhindered in place of the current social-distancing, lockdowns, masks etc is called out as false by this study.

Nomanking is right though that you don't necessarily need antibodies present to mount a immune response.

[Pierre]

Originally Posted by 1andrew1

Final nail in the coffin for those believing in herd immunity.


https://www.ft.com/content/f75418a9-...2-758635e906b1

Is it?

Or just more unproven speculation?

http://news.sky.com/story/coronaviru...overy-12115510

Then when you actually look behind the headline

Professor Wendy Barclay, an infectious diseases specialist and one of the researchers, said antibodies peak three to four weeks after symptoms and then drop away, as they do for related viruses.

She said: "Seasonal coronaviruses that circulate every winter and cause common colds can re-infect people after six to 12 months.

"We suspect that the way the body reacts to infection with this new coronavirus is similar to that."

There have so far only been a handful of documented cases of re-infection.

Dr Alexander Edwards, associate professor in biomedical technology at the University of Reading, said: "What is not clear is how quickly antibody levels would rise again if a person encounters the virus a second time.

"It is possible they will still rapidly respond, and either have a milder illness, or remain protected through immune memory.

"So even if the rapid antibody test is no longer positive, the person may still be protected from re-infection."

The study, which is yet to be peer reviewed, only measured antibodies.

It is possible that another arm of the immune system called T-cells, may remain active, but there is currently no available test for them.

I would put the nails away based on that

[BenMcr]

Originally Posted by nomadking

4) If herd immunity wasn't a fact, then people would've still been dying from Spanish Flu for the past 100 years.

My reading of it is that it was the associated health complications and recent world events which contributed to the high mortality rate. The Swine Flu outbreak in 2009 is the same strain as the Spanish Flu but I think the outcome was different because of its management.

How much 'herd immunity' factors into that I think it still up for review.

However although we are better at treating effects, the argument is still that we should try and stop it pandemics happening - not aim for 'herd immunity':

https://www.clinicalcorrelations.org...es-a-weakness/

Still, most of the deaths from the influenza of 1918 were due to bacterial pneumonia, for which we now have antibiotics. Currently, it is resistance that is the dilemma. In some parts of the United States, 35% or more of pneumococcal infections are resistant to the antibiotic of choice.[1] ARDS has a poor prognosis: despite advances in understanding its physiopathology, mortality rates remain as high as 40-46%.4 Though it is difficult to imagine a disaster on the scale of the 1918 infuenza almost a century later, a pandemic is not improbable. Now, in the face of a possible threat, efforts should be directed at prevention, which may be our best tool.

https://academic.oup.com/jid/article/195/7/1018/800918

The weight of evidence, supported by mathematical modeling data [98], suggests that if a novel virus as pathogenic as that of 1918 were to reappear today, a substantial proportion of a potential 1.9 million fatalities (assuming 1918 attack and case-fatality rates in the current US population) could be prevented with aggressive public-health and medical interventions. In an age of frequent air travel, we might expect global spread to proceed rapidly and to be difficult to control, but hardly much more so than the 1918 pandemic, in which most of the world was affected by W2 within a matter of a few weeks.

[jfman]

Originally Posted by Pierre

Is it?

Or just more unproven speculation?

http://news.sky.com/story/coronaviru...overy-12115510

Then when you actually look behind the headline

I would put the nails away based on that

It’s still a nail in the coffin for herd immunity either way. It means protecting the vulnerable is impossible unless you propose to lock them up forever.

What happens when you catch it a second, third, fourth time are unknown. Plus giving it billions of opportunities to mutate every year is a significant dice roll.

[nomadking]

Immunity DOESN'T mean the virus never ends up in your bloodstream again. After all, how else is the immune system meant to deal with it, if it's not in the blood?
Once somebody becomes infected for the first time or reacquires the virus, there is a window of time before that person becomes infectious and can pass it onto others. With a first time infection, the immune system takes too long to acquire immunity, and so people reach the infectious stage. With immunity and picking the virus up again, the immune system responds much quicker, and is likely to eliminate it before the person becomes infectious and can pass it onto others.
Herd immunity is about reducing transmission levels. The fewer people who reach the infectious stage, the fewer can become further infected.

[BenMcr]

Originally Posted by nomadking

Herd immunity is about reducing transmission levels. The fewer people who reach the infectious stage, the fewer can become further infected.

However we've never got herd immunity just by letting a disease spread.

https://www.jhsph.edu/covid-19/artic...h-covid19.html

How have we achieved herd immunity for other infectious diseases?
Measles, mumps, polio, and chickenpox are examples of infectious diseases that were once very common but are now rare in the U.S. because vaccines helped to establish herd immunity. We sometimes see outbreaks of vaccine-preventable diseases in communities with lower vaccine coverage because they don’t have herd protection. (The 2019 measles outbreak at Disneyland is an example.)

For infections without a vaccine, even if many adults have developed immunity because of prior infection, the disease can still circulate among children and can still infect those with weakened immune systems. This was seen for many of the aforementioned diseases before vaccines were developed.

[nomadking]

Herd immunity isn't about zero transmission, it's about greatly reducing the chances for transmission.
If only 1 in 100,000 people don't have immunity, then the chance of an infected person passing it on to somebody who isn't yet immune, is a lot less than where only 1 in 10 doesn't.
From your link.

What is herd immunity?
When most of a population is immune to an infectious disease, this provides indirect protection—or herd immunity (also called herd protection)—to those who are not immune to the disease.
For example, if 80% of a population is immune to a virus, four out of every five people who encounter someone with the disease won’t get sick (and won’t spread the disease any further). In this way, the spread of infectious diseases is kept under control. Depending how contagious an infection is, usually 50% to 90% of a population needs immunity to achieve herd immunity.
How have we achieved herd immunity for other infectious diseases?
Measles, mumps, polio, and chickenpox are examples of infectious diseases that were once very common but are now rare in the U.S. because vaccines helped to establish herd immunity. We sometimes see outbreaks of vaccine-preventable diseases in communities with lower vaccine coverage because they don’t have herd protection. (The 2019 measles outbreak at Disneyland is an example.)

The outbreaks arise from those who don't have herd protection.

[BenMcr]

My point is that acceptable and lasting herd immunity isn't something that has been achieved without a vaccine, which is what the link above says. Current proponents of herd immunity for Covid-19 want it to happen 'naturally' as an argument for lifting most restrictions before a vaccine is available.

From the 'Great Barrington Declaration':

Keeping these measures in place until a vaccine is available will cause irreparable damage, with the underprivileged disproportionately harmed.
...
The most compassionate approach that balances the risks and benefits of reaching herd immunity, is to allow those who are at minimal risk of death to live their lives normally to build up immunity to the virus through natural infection, while better protecting those who are at highest risk. We call this Focused Protection.

[OLD BOY]

Originally Posted by jfman

It’s still a nail in the coffin for herd immunity either way. It means protecting the vulnerable is impossible unless you propose to lock them up forever.

What happens when you catch it a second, third, fourth time are unknown. Plus giving it billions of opportunities to mutate every year is a significant dice roll.

Not in my opinion. Herd immunity has not been disproved. Worldwide, only a handful of people have succumbed a second time, and the reasons for that are unclear.

Protecting the vulnerable as I meant it does not require locking them up forever, but protecting them until the healthy population has had the virus run through them. This would get us more or less to where we need to be for us all to get back to normal.

Do that, and you minimise the risk of the virus reinfecting people as our defences wear down again, if indeed they do. These lockdowns are increasing these risks by keeping the virus alive for longer. Lockdowns are also increasing the risks of mutation.

---------- Post added at 16:34 ---------- Previous post was at 16:33 ----------

Originally Posted by Damien

Nomanking is right though that you don't necessarily need antibodies present to mount a immune response.

Correct.

[jfman]

If there was someone still clutching onto the end of that straw I’d have bet every penny I had on it being Old Boy.

[1andrew1]

Grim figures.

Coronavirus: 367 more COVID-19 deaths in UK - highest daily figure since May

Key points:

• UK records 22,885 more coronavirus cases and further 367 deaths
• Herd immunity hopes dashed as study shows COVID-19 antibodies fall rapidly after recovery
• Warrington enters Tier 3 restrictions - Nottingham, Broxtowe, Gedling and Rushcliffe to follow suit on Thursday
• Greater Manchester mayor Andy Burnham tells Lords that Tesco 'haven't taken a responsible attitude' towards making sure people wear face masks
• SAGE professor says only full lockdown has managed to contain virus so far

https://news.sky.com/story/coronavir...e-may-12116066

Originally Posted by OLD BOY

Not in my opinion. Herd immunity has not been disproved. Worldwide, only a handful of people have succumbed a second time, and the reasons for that are unclear.

Protecting the vulnerable as I meant it does not require locking them up forever, but protecting them until the healthy population has had the virus run through them. This would get us more or less to where we need to be for us all to get back to normal.

Do that, and you minimise the risk of the virus reinfecting people as our defences wear down again, if indeed they do. These lockdowns are increasing these risks by keeping the virus alive for longer. Lockdowns are also increasing the risks of mutation.

---------- Post added at 16:34 ---------- Previous post was at 16:33 ----------



Correct.

It’s a conundrum who to have more belief in - two epidemiological experts, with Ph.Ds from Johns Hopkins, whose primary research interests are in infectious disease, risk behaviors, and translational epidemiology, & infectious disease modeling, health economics, operational and implementation science, and classical epidemiology, or OLD BOY, whose primary research interest in pushing herd immunity with no supporting evidence whatsoever...

btw, witchcraft and wizardry have not been disproved, but due the lack of evidence (much like your position about herd immunity), very few people would put faith in them when treating infectious diseases...